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STUDIES 


INTERNAL  ANATOMY 
OF  THE  FACE. 


By  M.  H.  CRYER,  M.D.,  D.D.S., 

Professor  of  Oral  Surgery,  Department  of  Dentistry  of  the 
University  of  Pennsylvania. 


PHILADELPHIA: 

THE   S.  S.  WHITE   DENTAL   MFG.  CO., 
1901. 


COPYRIGHT,  190I,  BY   M.  H.  CRYER. 


PREFACE. 


Several  years  ago,  during  practical  surgical  work,  the  ob- 
servation of  considerable  variations  in  the  bones  of  all  parts 
of  the  head  led  the  writer  to  doubt  the  sufhciency  of  the  in- 
vestigations on  which  the  accepted  anatomy  of  those  parts 
is  based.  The  idea  of  unvarying  typical  form  was  too 
much  in  evidence  in  the  text-books;  variation  was  too  little  ac- 
counted with.  Talking  over  the  idea  with  Prof.  W.  F.  Litch, 
he  suggested  that  the  careful  study  of  a  series  of  dissections 
of  skulls  would  be  of  the  highest  value  and  would  probably 
settle  the  question  decisively.  Dr.  Litch  supplemented  his 
suggestion  by  the  gift  of  a  number  of  undissected  heads  with 
which  to  begin  the  work. 

This  was  the  beginning  of  an  investigation  during  which 
hundreds  of  skulls  have  been  dissected  and  studied.  This 
investigation  completely  overturned  the  writer's  conception  of 
what  was  meant  and  what  ought  to  be  meant  by  the  term 
typical.  There  is,  doubtless,  a  typical  or  typal  form  for  each 
bone,  but  it  is  not  often  found  in  nature.  If  we  were  to  pho- 
tograph a  thousand  temporal  bones,  for  example,  and  make 
a  composite  of  the  entire  number,  the  composite  would 
properly  be  accepted  as  figuring  the  typal  temporal.  It  is 
possible,  though  doubtful,  that  in  the  thousand  bones  two  or 
three  could  be  found  which  exactly  corresponded  with  the 
typal  bone  so  pictured.  This,  to  the  writer's  view,  is  strong 
testimony  that  the  typal  bone  is  ideal ;   that  the  actual  is  a 


IV  PREFACE, 

Variant.  It  is  with  these  variants  that  the  surgeon  and  dentist 
have  practically  to  deal. 

The  results  of  these  studies,  as  they  developed  from  time  to 
time,  have  been  communicated  to  the  medical  and  dental  pro- 
fessions through  papers  read  before  societies  and  printed  in 
the  medical  and  dental  journals.  Many  of  these  have  been 
published  in  the  Dental  Cosmos  and  in  the  Journal  of  the  American 
Medical  Association.  The  importance  of  the  work  has  been 
evidenced  by  the  incorporation  of  more  or  less  of  the  new 
discoveries  in  text-books  by  such  authors  as  Gray,  Gerrish, 
Burchard,  Kirk,  Marshall,  McCurdy,  D.  Braden  Kyle,  etc. 

The  presentations  of  this  work  which  have  heretofore  been 
made  have  been  fragmentary, — rather  in  the  form  of  partial 
reports  detailing  the  heretofore  unobserved  or  unrecorded  facts 
as  they  were  disclosed.  It  has,  therefore,  seemed  well  to  the 
writer,  inasmuch  as  the  work  has  now  progressed  to  a 
point  where  assurance  is  given  of  the  accuracy  of  the  conclu- 
sions, to  collate  and  present  the  results  in  an  assembled  form. 
From  the  very  nature  of  the  case  the  work  is  necessarily 
incomplete  ;  and  this  presentation  is  to  be  looked  upon  as  not 
in  any  sense  exhaustive  of  the  subject,  but  merely  as  an  exhibit 
of  the  present  status  of  the  investigation. 

What  is  claimed  for  it  is  that  it  is  a  demonstration  that 
typical  anatomy  is  ideal  anatomy.  It  also  demonstrates  the 
need  for  similar  systematic  study  of  the  anatomical  structure 
of  the  other  parts  of  the  body.  For  it  can  scarcely  be 
doubted  that  the  variations  noted  in  the  bony  structures  of  the 
head  and  face  will  be  found  coupled  with  equal  variations  of 
the  other  structures.  It  further  shows  that  the  text-book  by 
itself  is  insufficient  for  the  thorough  study  of  anatomy  ;  that  the 
only  true  and  complete  book  of  anatomy  is  the  body  itself  ; 


PREFACE.  V 

that,  therefore,  the  use  of  text-books  must  be  supplemented  by 
the  intimate  study  of  the  body. 

The  writer  is  greatly  indebted  to  Prof.  Thomas  C.  Stell- 
wagen  for  the  use  of  his  fine  collection  of  infant  skulls  and 
French  prepared  specimens  of  upper  and  lower  jaws,  from  the 
study  of  which  many  valuable  points  were  derived  ;  and  also  to 
Prof.  Edward  C.  Kirk  for  his  valuable  suggestions  during  the 
progress  of  this  work,  and  for  arrangements  made  by  him  for 
an  unlimited  supply  of  material  from  the  dissecting  rooms  of 
the  University  of  Pennsylvania.  The  writer  also  wishes  to 
acknowledge  his  indebtedness  to  the  late  Dr.  Harrison  Allen 
and  Profs.  E.  B.  Gleason  and  D.  Braden  Kyle  ;  and  also  for 
the  many  kind  suggestions  received  from  other  members  both 
■of  the  medical  and  dental  professions. 

The  thanks  of  the  writer  are  also  due  to  Mr.  Frank  L.  Hise 
for  his  helpful  assistance  in  the  preparation  of  the  work  for  the 
press. 

M.    H.    CRYER. 
Lansdowne,  Pa.,  July  ii,  1901. 


CONTENTS. 


PAGE 

Introductory i 

General  Considerations 4 . 

The  Mandible  or  Lower  Jaw 6 

The  Maxilla  or  Upper  Jaw 31 

The  Nasal  Foss^ .  46 

The  Maxillary  Sinus 59 

The  Frontal  Sinus 82 

The  Ethmoidal  and  Other  Cells  which   have  Their 

Outlet  in  the  Nasal  Foss.e 86 

Variations  in  the  Anatomical  Structures  of  the  Face.  89 

Effects  of  Pathological  Conditions  in  the  Region  of 

THE  Hiatus  Semilunaris , 113 

Impacted  Teeth 122 

Modification    of    the    Normal    Shape    of    the    Bone 

THROUGH  Abnormal  Forces 141 

The  Influence  of  Muscular  Action 150 

Hypertrophy  of  the  Gums  and  Alveolar  Process 160 

The  Relation  of  the  Two  Jaws 164 


LIST  OF  ILLUSTRATIONS. 


Abscess  opening  into  the  maxillary  sinus,  Figs.  54,  55,  56. 
Alveolar  process,  resorption  of,  Figs.  'JT,  78. 
Alveoli  of  teeth,  Figs.  7,  21. 
Ankylosis,  false.  Figs.  132,  133,  134,  135,  140. 
muscular  action  in,  Fig.  140. 
true.  Figs.  136,  137,  138,  I39- 
Anterior  view  of  a  vertical  section  in  the  region  of  the  crista  galli,  middle  of 
orbit  and  molar  teeth,   showing  effect  of  dental  abscess  in  floor  of  the 
maxillary  sinus,  Fig.  56. 
of  a  vertical  transverse  section  from  skull  of  an  old  person,  showing  thin- 
ness of  walls  of  maxillary  sinus,  also  membranous  septa  of  sinus.  Fig.  43. 
of  a  vertical  transverse  section  of  right  side  of  face.  Fig.  34. 
of  a  vertical  transverse  section  of  the  face,  Figs.  43,  56,  61,  65,  66,  68,  70,  71, 

^2,  74,  75,  86,  90,  91,  107. 
of  a  vertical  transverse  section  of  the  skull  of  an  old  person,  Fig.  75. 
of  vertical  transverse  sections  showing  communication  between  frontal  and 

maxillary  sinuses,  Figs.  86,  90,  91. 
of  vertical  transverse  section  through  the  center  of  the  orbits,  nasal  cham- 
ber, and  maxillary  sinus.  Figs.  66,  72,  ']2„  74,  75- 
Antero-lateral  view  of  upper  and  lower  jaws,  with  outer  cortical  plate  re- 
moved, Figs.  4,  5,  30. 
Antero-posterior  division  of  the  maxillary  sinus  and  molar  teeth,  Figs.  31,  54. 
through  the  center  of  the  orbit,  maxillary  sinus,  and  molar  teeth.  Figs.  45, 

46,  47,  48,  49,  51,  52,  53,  97. 
through  the  maxillary  sinus.  Figs.  31,  41,  42,  44,  45,  46,  47,  48,  49,  51,  52,  53. 
54,  60,  85,  97. 
Antero-posterior  section  of  frontal  sinus,  orbit,  and  maxillary  sinus,  Fig.  60. 
of  nasal  chamber.  Figs.  59,  77,  84,  88,  95,  96,  97,  98. 
within  the  nasal  chamber,  with  middle  turbinate  bone  and  portion  of  the 

wall  turned  up.  Fig.  39. 
showing  communication  between  the  frontal  and  maxillary  sinuses.  Figs. 
85,  88,  89. 
Antero-posterior  sections  of  the  nasal  chamber  and  maxillary  sinus.  Fig.  97. 

Cells,  anterior  ethmoidal,  Figs.  39,  63. 

middle  ethmoidal.  Figs.  10,  25,  39,  63,  100,  103. 

of  crista  galli.  Figs.  74,  82,  90,  91. 

of  orbital  process  of  the  palate  bone.  Figs.  45,  46,  47,  48,  60. 

posterior  ethmoidal.  Figs.  36,  39,  63. 
Communication  between  frontal  and  maxillary  sinuses.  Figs.  85,  86,  87,  88,  89. 

90,  91,  92,  93. 
Comparative  sizes  of  upper  jaws,  oral  surfaces  of,  Fig.  129. 
Cribriform  tube  of  mandible.  Figs.  4,  5,  6,  8. 


X  LIST    OF    ILLUSTRyVTIONS. 

Crista  galli,  Figs.  lo,  25,  56,  74. 
Crystalline  lens,  Figs.  10,  25. 

Eustachian  orifice,  Figs.  32,  39. 

External  wall  of  nasal  fossae.  Figs.  32,  33,  39,  50,  51,  59,  yy,  8.1,  95,  96,  no. 

External  walls  of  the  nasal  chamber  showing  the  left  frontal  sinus  extended 

over  to  the  right  of  the  median  line,  Fig.  59. 
Extraction,  accidents  of,  Fig.  58. 

False  ankylosis,  Figs.  132,  133,  134,  135,  140. 
Flat-head  North  American  Indians,  Figs.  122,  123. 
Fractures  of  the  alveolar  process,  Fig.  58. 

Frontal  sinus.  Figs.  32,  34,  35,  39,  59,  60,  61,  62,  89,  90,  92,  93,  98. 
Front  view  of  asymmetrical  skull,  showing  the  rieht  side  of  the  face  fuller 
than  the  left  side.  Fig.  64. 

Ground  section  of  teeth.  Fig.  9. 

Head,  vertical  transverse  bilateral  section  of.  Figs.  10,  25. 

Hiatus  semilunaris.  Figs.  10,  25,  26,  39,  79,  81,  8s,  86,  87,  88,  89,  90,  92. 

Horizontal  section  of  nasal  chamber  and  maxillary  sinus,  Figs.  38,  55,  57,  81. 

through  orbit  and  ethmoidal  cells.  Figs.  100,  103. 
Horizontal   sections  through  the  upper  portion   of  the  nasal   chamber  and 

anterior  fossa  of  the  brain-case,  Figs.  99,  100,  loi. 
Hypertrophy  of  gums.  Figs.  143,  144,  145,  146,  147. 

Impacted  canines.  Figs.  37,  108,  109,  no,  iti,  it2. 

central  incisor,  Figs.  105,  106,  108,  113. 

lateral  incisor.  Fig.  108. 

lower  third  molar  teeth.  Figs.  116,  117,  118.  119,  120,  I2T. 

supernumerary  upper  lateral  tooth.  Fig.  114. 

upper  third  molar.  Figs.  107,  ns. 
Infraorbital  sinus,  Figs.  31,  54,  79,  92. 

Interior  view  of  the  wall  of  the  nasal  fossa,  showing  portions  of  the  palatal 
roots  of  the  first  and  second  molar  teeth  in  the  floor  of  the  nose.  Fig.  77. 

Mandible,  aged.  Figs.  3,  141,  142,  150.  151. 

alveoli  of.  Fig.  7. 

ankylosed  typical,  shape  of.  Figs.  136,  137,  138,  139. 

anterior  transverse  section  of,  posterior  view  of,  Fig.  11. 

anterior  view  of.  Fig.  23. 

Caucasian;  Figs.  2,  131. 

equilateral  triangle  of.  Figs.  19,  20. 

Fan  tribe.  West  Africa,  Figs.  2,  131. 

ground  section  of  six  anterior  teeth  and  two  premolars,  Fig.  9. 

horizontal  sections  of.  Figs.  14,  15. 
•     infant.  Fig.  i. 

infant's,  cross-section  of,  Figs.  40,  148. 

internal  structures  of,  two  views  of  metal  casts  of.  Fig.  13. 

lateral  view  of.  Fig.  22. 

longitudinal  division  of,  showing  cancellated  tissue,  Fis.  12. 

nerve  tissue  in  cribriform  canals.  Fig.  8. 

of  aged  persons.  Figs.  3,  150,  151. 

prognathous,  Fig.  131. 


LIST    OF    ILLUSTRATIONS.  XI 

Mandible,  senile.  Fig.  3. 

showing  cribriform  tubes,  Figs.  4,  5,  6,  8,  30. 

showing  deciduous  and  permanent  teeth,  Figs.  29,  104. 

showing  sockets  of  teeth.  Fig.  7. 

transverse  section  of.  Figs.  11,  16,  17. 

triangular  shape  of,  Figs.  19,  20. 

U-shaped  cortical  portions  of.  Figs.  10,  11. 

with  external  cortical  portion  of  bone  removed.  Figs.  4.  5,  6,  8,  30. 

with  misplaced  third  molar  tooth.  Fig.  18. 

with  the  cortical  portion  of  bone  removed  from  the  body,  Fig.  5. 
Mandibular  triangle.  Figs.  19,  20. 
Maxilla,  alveoli  of,  Fig.  21. 

antero-posterior  division  of.  Fig.  54. 

showing  lachrymal  ducts,  Fig.  37. 

typical.  Fig.  24. 
Maxillary  sinus,  antero-posterior  section  of.  Figs.  31, .41,  42,  44,  45,  46,  47,  48, 

.     49,  SI,  52,  53,  54,  60,  85,  97,  141. 

horizontal  section  of.  Figs.  38,  55,  57,  81,  99. 

penetrating  malar  bone.  Fig.  76. 

transverse  section  of.  Figs.  10,  25.  26,  27,  34,  35,  36,  40,  43,  56,  61,  65,  66,  67, 

68,  69,  70,  71,  72,  Tz,  74,  75,  76,  79,  80,  82,  83,  86,  87,  90,  91,  92,  93,  94, 
107,  112,  148. 

Metal  cast  of  cancellated  tissue  of  mandible.  Fig.  13. 
Mu.scular  action  in  ankylosis,  Fig.  140. 

Nasal  chamber,  horizontal  section  of.  Figs.  38,  55,  57,  63.  81,  99,  100. 
Jateral  wall  of,  Figs.  32,  23,  39,  5o,  51,  59,  77,  84,  88,  95,  96,  97,  no. 
vertical  transverse  section  of.  Figs.  61,  66,  67,  68,  69,  70,  71,  72,  72,  74-  75-  80, 
82,  83,  86,  87,  90,  9L  92,  93,  94. 
Nasal  septum,  Figs.  10,  25,  35,  36,  37,  38,  63,  66,  67,  68,  69,  70,  71,  72,  73,  74,  75, 

80,  81,  82,  83,  90,  91,  92,  93,  94,  95,  96. 
Nutritional  supply  of  upper  posterior  teeth.  Fig.  31. 

Occlusion,  typical,  Figs.  22,  23. 

Pathological  conditions  of  the  nasal  chamber,  Figs.  95,  96. 
Perforation  of  tooth  in  drilling.  Fig.  28. 
Position  of  roots  in  jaws.  Figs.  4,  5,  8,  9,  11,  12,  14.  15. 

Posterior  view  of  a  vertical  transverse  section,   showing  communication,  be- 
tween the  frontal  and  maxillary  sinuses,  Figs.  87,  90,  92,  93,  94. 
of  the  right  side  of  face.  Fig.  35. 
of  two  vertical   sections   showing  variations   in   depth   of  face  and  of  the 

internal  structures,  Figs.  82,  83. 
of  vertical   section  through  the.  orbit,  maxillarv  sinus,   and  posterior  eth- 
moidal cells.  Fig.  80. 
of  vertical  transverse  section  of  face,  Figs.  26,  27,  43,  56,  61,  65,  66,  67,  68, 

69,  70,  71,  73,  74.  80,  82,  83,  87,  90,  92,  93,  94,  112. 
Prognathous  skull,  Fan  tribe  negro,  Figs.  124,  125,  126. 

of  a  negro  with  eighteen  teeth  in  upper  jaw,  Figs.  127,  128. 

Relations  of  deciduous  and  permanent  teeth  at  six  years,  Fig.  29. 

of  the  jaws.  Figs.   10,  25,  40,  148,  149,  150,  151. 
Roots  of  teeth  passing  out  through  cortical  bone  of  jaw.  Fig.  18. 
Rudimentary  fourth  molars,  Figs.  128,  129,  130. 


Xll  LIST   OF   ILLUSTRATIONS. 

Section  showing  diseased  condition  of  inner  wall  of  orbit,  Fig.  102. 

showing  greater  portion  of  the  upper  jaw.  Fig.  y], 

through  the  maxillo-malar  articulation.  Fig.  76. 
Separating  infraorbital  sinus.  Fig.  31. 
Skull,  adult.  Figs.  22,  23,  24,  150,  151. 

asymmetrical.  Figs.  64,  65. 

of   a   fully   developed   embryo    cut    vertically   through   the   first   deciduous 
molars,  Figs.  40,  148. 

of  aged  person.  Figs.  150,  151. 

of  Caucasian,  Figs.  124,  125,  126. 

of  Fan  tribe  negro.  West  Africa.  Figs.  124,  125,  126. 

of  Flat-head  Indian,  Figs.  122,  123. 

of  six-year-old  child.  Figs.  29,  104. 

prognathous,  Figs.  124,  126,  127. 

typical,  Figs.  22,  23,  24. 
Sockets  of  the  teeth.  Figs.  7,  21. 
Sphenoidal  sinus.  Figs.  39,  51,  63,  84. 
Supernumerary  teeth.  Figs.  105,  114. 

Teeth,  impacted.  Figs,  zi,  105,  106,  107,  108.  109,  no,  in,  112,  113,  114,  115, 

116,  117,  118,  119,  120,  121.     . 
rudimentary,  Figs.  127,  128,  129,  130. 
supernumerary.  Figs.  105,  114. 
Temporo-mandibular  articulation,  modification  of.  Figs.  141,  142. 
Transverse  section  of  face.  Figs.  10,  25,  26,  27,  34,  35,  36.  40,  43,  56,  61,  65,  66, 

67,  68,  69,  70,  71.  72,  73,  74,  75,  79,  80.  82,  83,  86,  87,  90,  91,  92,  93,  94, 

107,  112,  148,  149. 
True  ankylosis,  mandibles  of.  Figs.  136,  137. 

skulls  of.  Figs.  138,  139. 
Two    antero-posterior    sections   made   by   dividing   the    orbit    and    maxillary 

sinus  vertically,  showing  conical  elevations  over  the  roots  of  the  various 

teeth.  Fig.  41. 
Two  illustrations  showing  variations  in  the  depth  and  size  of  the  external 

walls  of  the  nasal  chambers.  Fig.  84. 
Two  sections  showing  diseased  condition  of  ethmoidal  cells,  Fig.  103. 

Under  surface  of  two  upper  jaws,  showing  comparison  in  size,  Fig.  129. 
Upper  and  lower  jaws,  anterior  view  of,  Fig.  149.    ' 
Upper  jaw,  anterior  lateral  view  of.  Figs.  4,  30. 

anterior  view  of,  Fig.  yi- 

antero-posterior  section  of.  Figs.  31,  41,  42,  45,  46,  47,  48,  49,  52,  53,  54,  97. 

showing  deciduous  and  permanent  teeth.  Fig.  29. 

transverse  section  of.  Figs.  10,  25;  26,  27,  40,  43,  56. 

under  surface  and  alveoli  of  the  various  teeth.  Fig.  21. 

tmder  surface  of,  showing  occluding  surfaces  of  teeth.  Figs.  24,   126,   128, 
129,  130. 

vertical  transverse   section  of,   showing  ostium  maxillare  and   infraorbital 
sinus,  Fig.  79. 

Vertical  antero-posterior  division  through  the  frontal  sinus,  orbit,  and  max- 
illary sinvis.  Fig.  44. 

Vertical  transverse  section  of  asymmetrical  skull.  Figs.  65,  66,  67,  68,  69, 
70,  71. 


INTRODUCTORY. 


Carefully  conducted  studies  of  numerous  dissections 
prove  conclusively  that  many  of  the  stereotyped  descriptions 
of  the  internal  anatomy  of  the  face  are  not  justified  by  the 
facts;  and  that,  therefore,  the  hard  and  fast  rules  for  surgical 
procedures  founded  on  these  descriptions  do  not  adequately 
cover  the  ground.  In  pursuance  of  these  studies,  hundreds  of 
sections  of  the  facial  region  have  been  cut  and  examined.  The 
lesson  that  they  teach  is  that  the  accepted  descriptions  are 
to  be  received  as  only  general  truths,  and  that  they  cannot  be 
depended  upon  or  followed  literally  as  a  guide  for  the  surgeon 
or  dentist.  The  results  of  these  studies  afiford  a  basis  for  the 
explanation  of  the  failure  of  many  operations  conducted  on 
the  lines  of  the  accepted  anatomical  descriptions,  and  which 
have  been  regarded  as  merely  the  natural  percentage  of  failure; 
whereas,  they  have  probably  been  due  to  variations  in  the 
parts  clearly  within  the  limits  of  normality,  as  will  be  shown 
by  many  illustrations. 

Anatomical  Variations.  No  man  who  spends  any  consid- 
erable portion  of  his  time  in  the  study  of  anatomy — that  is, 
in  actual  dissections — can  fail  to  note  how  great  is  the  number 
of  anatomical  variations  he  meets  with.  So  common  are  these 
that  it  cannot  be  said  with  exactness  which  are  typical  anat- 
omy and  which  are  anatomical  variations.  In  other  words, 
anatomy  as  a  study  is  not  to  be  classed  among  the  exact  sci- 
ences. It  is  not  meant  by  this  that  there  is  not  such  a  basis 
of  anatomical  science  that  general  rules  cannot  be  laid  down, 
but  the  more  closely  the  subject  is  studied  the  more  variations 
as  to  details  are  recorded.    To  be  sure,  given  the  mandible  of 

I  I 


2  INTERNAL   ANATOMY    OF    THE    FACE. 

an  animal,  a  femur,  or  even  a  tarsal  bone,  the  nature  of  the 
associated  bones,  their  sizes,  positions,  and  forms  can  be  de- 
duced. Admitting  this,  however,  there  are  still  as  many  varia- 
tions in  the  internal  anatomy  as  there  are  differences  in  the 
external  appearances. 

Especially  is  this  true  of  the  anatomy  of  the  human  head, 
as  it  is  modified  by  climate,  race,  age,  disease,  occupation,  and 
many  other  conditions. 

Climate.  Climate  and  consequently  environment  have  a 
great  influence  in  modifying  the  development  of  the  bones 
of  the  head,  as  is  demonstrated  in  the  differing  formations  of 
the  skulls  of  the  great  races  of  the  world;  and  more  markedly 
in  branches  of  the  same  race  living  under  diverse  climatic  and 
social  conditions. 

Age.  The  changes  produced  by  age  are  very  marked. 
The  skull  consists  of  bones  of  both  cartilaginous  and  mem- 
branous origin.  In  the  fetus  and  infant  these  bones  are  soft 
and  yielding;  they  receive  deposits  of  calcic  material,  be- 
coming harder  and  harder  as  age  advances  until  the  degenera- 
tion of  senility  sets  in.  In  the  jaws,  constant  changes  are 
caused  by  the  development,  eruption,  and  loss  of  teeth  and 
the  consequent  alterations  of  the  alveolar  process. 

Disease.  Disease  causes  anatomical  changes  in  the  bony 
structures  as  well  as  in  the  other  tissues  of  the  body.  In  the 
presence  of  some  disorders  of  the  nutritive  system,  the  bones 
may  fail  to  become  infiltrated  with  a  sufficient  quantity  of 
calcic  material,  which  would  have  the  effect  of  leaving  them 
soft  and  yielding;  or,  on  the  other  hand,  an  undue  proportion 
of  calcium  salts  may  be  incorporated  into  the  bones,  with  the 
opposite  effect  of  making  thein  hard  and  unyielding,  thus 
modifying  the  physiological  functions  in  which  they  are  con- 
cerned. 

Occupation,  Diet,  etc.  Occupation  will  modify  the  shape 
and  character  of  the  face  and  head,  especially  in  youth.  Those 
who  are  studious  and  pass  an  indoor  life  are  likely  to  have  a 
more  delicate  development  of  the  face,  with  a  larger  brain-case 


INTRODUCTORY. 


than  those  who  are  brought  up  to  a  laborious  outdoor  Hfe. 
The  mastication  of  coarser  foods  wih  develop  the  muscles  of 
mastication  and  their  bony  attachments.  Numerous  other 
facts  might  be  cited  to  show  the  influence  of  personal  habit 
upon  the  course  of  anatomical  development. 

Asymmetry.  There  are  even  variations  in  the  same  indi- 
vidual in  the  shape,  size,  and  markings  of  the  two  sides  of  the 
face.  In  the  bilateral  bones  such  as  the  frontal,  sphenoid, 
vomer,  ethmoid,  and  mandible,  one  side  is  usually  found  to 
differ  from  the  other.  In  the  hoinonymous  bones,  as  the  max- 
illae, the  malar,  the  lachrymal,  the  turbinate,  and  the  palate 
bones,  the  same  variations  are  observed.  This  being  the 
case,  it  will  be  readily  understood  that  the  internal  openings 
and  spaces,  as  the  mouth,  the  nasal  chambers,  the  orbits,  the 
maxillary,  frontal,  and  sphenoidal  sinuses,  the  ethmoidal  and 
other  cells,  will  differ  accordingly. 

Diagnostic  Importance.  It  is  clear  that  variations  of  the 
nature  referred  to  must  have  a  direct  bearing  on  the  diagnosis 
of  morbid  conditions  for  which  there  is  no  plainly  readable  out- 
ward explanation,  and  even  more  so  on  the  performance  of  op- 
erations for  their  relief.  A  knowledge  of  these  variations  will 
point  the  way  to  an  understanding  of  many  otherwise  obscure 
and  doubtful  lesions.  It  will  also  show  why,  for  example,  fol- 
lowing the  typical  anatomy,  the  surgeon  seeking  to  open  into 
the  antrum  will  occasionally  enter  the  nasal  cavity  instead.  It 
would  seem  that  to  the  surgeon,  and  more  especially  to  the 
dentist,  such  information  is  a  necessity. 

The  main  object  of  this  volume  is  to  present  a  digest  of 
some  newly  revealed  facts  relating  to  the  internal  anatomy  of 
the  face, — facts  which  have  an  important  bearing  on  all  sur- 
gical operations  involving  this  region,  and  especially  on  the 
work  of  the  dentist  and  the  rhino! ogist.  In  this  view,  the 
aim  will  be  to  call  attention  to  misconceptions  of  the  actual 
conditions,  to  correct  errors  which,  having  found  currency, 
have  been  commonly  accepted,  and  more  especially  to  enforce 
the  idea  that  a  blind  following  of  typical  descriptions  is  likely 
to  lead  to  disaster. 


INTERNAL   ANATOMY    OF   THE    FACE. 


GENERAL  CONSIDERATIONS. 


Anatomical  Structures.  The  anatomical  bony  structures 
of  the  facial  region  include  the  framework  of  the  external  face 
and  the  walls  of  the  various  cavities  and  air  spaces  of  the 
internal  face.  As  with  other  bones,  they  consist  of  a  cortical 
outer  wall  inclosing  cancellated  tissue,  the  latter  being  ex- 
tremely fine  and  delicate  in  many  cases,  in  some  instances  be- 
coming so  attenuated  as  to  almost  be  lost.  The  exterior  cor- 
tical surfaces  are  covered  with  a  true  periosteum,  while  the  in- 
terior surfaces,  those  looking  toward  the  internal  cavities,  as 
the  mouth,  nasal  chamber,  the  frontal,  maxillary,  and  sphe- 
noidal sinuses,  and  the  ethmoidal  cells,  are  covered  by  a  muco- 
periosteum.  From  these  characteristics,  the  former  are 
known  as  non-mucous,  and  the  latter  as  mucous  or  mucoid  sur- 
faces. It  is  important  to  consider  the  difference  in  these  sur- 
faces in  the  treatment  of  some  of  the  diseases  of  the  bones. 

The  dense  exterior  or  non-mucous  surface  is  roughened  at 
various  points  for  the  attachment  of  muscles.  The  exterior 
cortical  portion  varies  in  thickness  according  to  the  amount 
of  work  to  which  it  is  subjected  or  the  protection  it  has  to 
afford.  The  greatest  thickness  is  found  in  the  mandible,  the 
active  bone  of  mastication,  which  occupies  a  position  in  the 
face  where  it  is  peculiarly  exposed  to  the  effects  of  external 
forces,  as  blows,  etc. 

The  inner  or  mucous  surfaces,  while  dense  and  compact,  are 
thinner  and  more  delicate,  and  smoother.  They  are  marked 
by  depressions  for  the  lodgment  of  the  mucous  glands,  by 


GENERAL    CONSIDERATIONS.  5 

grooves  for  the  passage  of  the  nerves  and  vessels,  and  are 
roughened  for  the  attachment  of  the  muscles. 

Cancellated  Structure.  The  cancellated  tissue  found  be- 
tween the  plates  of  cortical  bone  varies  in  thickness  and  com- 
pactness according  to  the  density,  the  position,  and  the  func- 
tions of  the  bone.  The  arrangement  of  the  trabeculae  is  an 
interlacing  network.  The  functions  of  the  cancellated  tissue 
are  to  give  bulk  to  the  bone  where  required  and  to  diffuse 
shock.  Through  it  pass  the  nerves  and  vessels  to  supply  local 
structures  and,  by  means  of  bony  canals  or  tubes,  the  more 
distant  parts.  The  bones  of  the  head  contain  many  canals 
and  foramina  for  this  last-named  purpose,  thus  differing  ma- 
terially from  the  other  bones  of  the  body.  This  is  a  fact  of 
surgical  importance,  for  when  these  bones  have  become  al- 
tered either  by  breaking  down  of  the  tissue  or  by  abnormal 
growths  encroaching  upon  the  foramina  or  canals,  the  func- 
tions of  the  nerves  and  vessels  are  interfered  with,  thus  af- 
fecting not  only  adjacent  tissues,  but  as  well  parts  of  the  face 
and  body  remote  from  the  seat  of  the  lesion,  causing  abnor- 
malities in  the  area  of  distribution,  as  atrophy,  neuralgia,  etc. 


INTERNAL    ANATOMY    OF    THE    FACE. 


THE  MANDIBLE  OR  LOWER  JAW. 


The  Mandible.  The  mandible  or  inferior  maxillary  bone 
is  symmetrical  in  its  general  shape,  although  one  side  may  and 
usually  does  differ  from  the  other.  It  presents  for  study  a 
body  horizontal  in  direction,  with  two  rami  extending  upward 
to  the  articulation  in  the  anterior  portion  of  the  glenoid  fossae 

Fig.   I. 


C  D 

Four  mandibles   ranging  from   birth  to   eighteen   months.     A,   at  birth ; 
months;    C,  at  six  months;    D,  at  eighteen  months. 


5,   at   three 


of  the  temporal  bones.  The  angle  (gonion)  formed  by  the 
union  of  the  lower  border  of  the  jaw  and  the  posterior  border 
of  the  ramus  varies  considerably  at  different  periods  of  life. 

Figs.  I,  2,  and  3  are  views  of  the  external  cortical  surfaces  of 
the  normal  lower  jaw  at  various  ages,  showing  progressive 
changes  in  the  angle  between  the  rami  and  the  body  of  the 
bone,  as  life  passes.  At  birth  (A,  Fig.  i)  the  angle  is  very 
obtuse,  but  as  the  teeth  develop  and  erupt  it  becomes  less 


THE    MANDIBLE    OR    LOWER    JAW.  7 

and  less  obtuse,  until  about  the  time  the  last  of  the  permanent 
teeth  are  erupted  it  is  almost  a  right  angle,  as  shown  in  Fig.  2. 
The  difference  in  direction  is  due  to  the  general  separation  of 
the  jaws  by  the  growth  of  the  alveolar  process  and  the  pro- 

FlG.  2. 


/ 


/ 


Two  mandibles.     A,  from  an  adult  of    the    Fan    tribe    of    West    Africa.     B,    from    an 
adult  Caucasian. 

jection  of  the  teeth  into  the  space  between  them.  As  the 
teeth  wear  away,  or  when  they  are  extracted,  the  process  is 
resorbed,  the  horizontal  planes  of  the  jaws  approach  each 
other  more  closely,  and  the  angle  again  becomes  obtuse.'^ 
(See  Fig.  3,  B.) 


*See  chapter  on  "The  Relation  of  the  Two  Jaws,"  page  164. 


5  INTERNAL   ANATOMY    OF   THE    FACE. 

The  body  of  the  jaw,  in  transverse  section,  shows  a  U-shaped 
cortical  or  dense  bony  structure,  the  arms  of  the  U  terminating 
in  tlie  plates  of  the  alveolar  process, — outer  and  inner, — which 
are  composed  of  a  modified  cortical  bone  with  no  definite  line 
of  demarkation  between  them  and  the  body  of  the  bone  proper. 

Fig.  3. 


Two  mandibles  of  aged  persons.    A,  showing  but  a  slight  change  in  the  angle,   or 
gonion,   while  in  B  there  is  great  change  from  that  of  adult  life. 


The  bone  proper  is  covered  with  a  true  periosteum,  the  alve- 
olar process  with  muco-periosteum,  the  latter  being  thick  and 
dense  and  containing  few  mucous  glands.  It  is  commonly 
known  as  gum  tissue.  The  space  between  the  arms  of  the  U 
is  filled  with  fine  trabecule  forming  the  cancellated  structure. 
The  roots  of  the  teeth  are  imbedded  within  this  cancellated 


THE    MANDIBLE    OR    LOWER    JAW.  9 

structure,  each  root  being  surrounded  with  thin,  compact 
bony  tissue,  which  approaches  the  cortical  bone  in  density, 
but  is  cribriform  (sieve-Hke)  in  character.  (See  Figs.  4,  5, 
and  7.) 

Fig.   4. 


ki4s<v>!V- 


Anterior  lateral  view  of  upper  and  lower  jaws,  with  the  external  cortical  portion  of 
bone  covering  the  roots  of  the  teeth  removed,  exposing  the  cancellated  tissue,  the  roots, 
and  the  cribriform  tubes. 


Fig.  7  is  an  upper  view  of  the  mandible  with  the  teeth  re- 
moved, showing  single  sockets  for  the  ten  anterior  teeth  and 
double  sockets  for  the  six  molars.  The  shapes  of  the  sockets 
as    shown    correspond    with    the    transverse    section    of    the 


lO 


INTERNAL    ANATOMY    OF    THE    FACE. 

Fig.  ^. 


Mandible  with  the  cortical  portion  of  bone  removed  from  the  body. 

Fig.  6. 


Cribriform  tube  (inferior  dental  canal)  of  the  lower  jaw  isolated. 


THE    MANDIBLE    OR    LOWER    JAW. 


II 


various  teeth  at  the  level  of  the  margins.     The  septa  between 
the  sockets  are  cribriform  in  character. 

Cribriform   Tube.      Through   the   cancellated   tissue  passes 
the  so-called  inferior  dental  canal,  which  is,  however,  more 

Fig.  7. 


View  from  above  of  mandible  from  which  all  the  teeth  have  been  removed,  showing 
the  cribriform  character  of  the   septa  of  the  sockets  of  the  teeth. 

accurately  described  by  the  term,  "cribriform  tube  of  the  man- 
dible." The  function  of  this  tube  is  to  afford  a  protective 
passage  for  the  inferior  dental  nerve  and  the  blood-vessels. 

The  cribriform  tube  passes  downward  and  forward  from  the 
inferior  dental  foramen,  at  first  along  the  inner  cortical  por- 
tion, then,  after  it  leaves  the  ramus,  gradually  crossing  over 
through  the  cancellated  tissue  toward  the  outer  cortical  por- 
tion and  downward  toward  the  border  of  the    U-shaped  space. 


12  INTERNAL    ANATOMY    OF    THE    FACE. 

As  it  approaches  the  mental  foramen,  its  course  is  near  the 
outer  cortical  portion  and  along  the  lower  border  of  the  can- 
cellated tissue,  passing  beneath  the  foramen  to  its  termination 
near  the  roots  of  the  incisor  teeth.  This  tube  can  be  removed 
from  a  normal  jaw  or  isolated  as  shown  in  Fig.  6,  taken  from 
a  specimen  in  which  the  cortical  and  cancellated  tissues  have 
been  cut  away,  exposing  the  cribriform  tube.  Figs.  4,  5,  and  6 
show  that  the  cribriform  tube  is  an  independent  structure,  not 
merely  a  canal  through  the  bone.  In  Fig.  4  it  will  be  noticed 
that  a  portion  of  the  outer  wall  of  the  tube  has  been  removed, 
while  in  Fig.  5  the  wall  is  left  intact,  showing  its  tube-like 
form.  The  outer  wall  of  the  tube  in  the  region  of  the  second 
and  third  molars  is  extremely  well  shown  in  Fig.  5. 

As  the  tube  passes  along  the  jaw  its  cribriform  character 
becomes  more  and  more  marked  until,  beneath  the  first  molar 
tooth,  it  becomes  so  opened,  probably  by  a  sort  of  stretching 
process  coincident  with  the  growth  of  the  bone,  that  the  tube- 
like formation  is  almost  lost,  as  is  well  shown  in  Fig.  4. 
Further  forward  it  again  resumes  its  original  character. 
This  main  cribriform  tube  gives  off  lesser  branch  tubes 
which  afford  passage  for  the  nerves  and  vessels  to  the  sub- 
stance of  the  bone;  also,  in  more  or  less  curved  course  to  the 
roots  of  each  tooth.  The  branch  tube  for  the  accommodation 
of  the  nerves  and  vessels  to  the  mental  foramen  is  usually 
given  off  slightly  anterior  to  the  foramen,  passing  backward 
from  the  main  tube  to  the  foramen.  This  is  almost  invariably 
the  rule, — ruamely,  that  the  tube  to  the  mental  foramen  is  in 
the  form  of  a  return  or  recurrent  canal,  though  occasionally 
it  passes  from  the  main  tube  as  it  approaches  the  foramen.  The 
recurrent  tube  is  well  shown  in  Figs.  4  and  5.  In  the  former, 
the  anterior  well  of  the  mental  foramen  has  been  cut  away, 
and  in  the  latter,  a  narrow  piece  of  paper  has  been  passed 
through  the  foramen  into  the  recurrent  tube,  showing  its 
direction. 

The  Dental  Branches.  The  small  lateral  tubes  which  serve 
as  nerve  and  vessel  conduits  to  the  roots  of  the  teeth  posterior 


THE    MANDIBLE   OR   LOWER   JAW.  I3 

to  the  mental  foramen  are  given  off  from  the  main  tube  and 
pass  upward  and  forward  in  a  more  or  less  curved  direction, 
the  degree  of  curvature  varying  according  to  the  position  of 
the  teeth.  Those  going  to  the  third  molar  are  nearly  vertical 
in  direction.  In  those  going  to  the  second  molar  the  forward 
direction  is  greater;  in  those  to  the  first  molar  this  forward 
direction  is  increased  still  more,  while  those  to  the  second 
premolar  have  the  longest  curve  of  all.  Sometimes  the  tube 
passing  to  the  second  premolar,  instead  of  beginning  at  the 
main  tube,  is  found  as  an  offshoot  of  that  going  to  the  anterior 
root  of  the  first  molar.  The  small  tubes  going  to  the  first 
premolar  and  the  canine  are  branches  of  the  recurrent  tube  of 
the  mental  foramen,  and  are  curved  slightly  backward  as  they 
pass  upward  to  the  roots.  In  the  unusual  cases  where  the 
branch  from  the  mental  foramen  is  not  recurrent,  but  given  off 
as  the  main  tube  approaches  the  foramen,  the  latter  branches 
for  these  two  teeth  pass  directly  from  the  main  tube,  and  with 
a  slight  forward  curvature.  The  tubes  for  the  supply  of  the 
incisors  are  also  branches  of  the  main  tube,  and  curve  slightly 
forward  as  they  pass  upward  to  the  roots. 

Method  of  Growth.  The  cortical  U-shaped  portion  of  the 
bone  is  the  framework  of  the  jaw,  its  supporting  structure;  it 
increases  in  length  and  breadth  in  a  different  manner  from 
its  contents.  It  is  likely  that  it  grows  by  an  interstitial  pro- 
cess, each  half  having  three  fixed  points  between  which  the 
growth  occurs, — viz.,  the  ramus,  the  mental  foramen,  and  the 
symphysis  menti  (or  gnathion).  There  is  no  doubt  that  the 
distance  between  these  points  increases,  though  the  growth 
between  the  symphysis  and  the  foramen  does  not  occur  at  the 
same  time  as  that  between  the  foramen  and  the  ramus.  The 
periods  of  growth  in  these  regions  seem  to  correspond  with  the 
time  of  development  and  eruption  of  the  teeth  of  the  localities 
concerned.  Thus,  the  increase  between  the  mental  foramen 
and  the  symphysis  menti  occurs  during  the  time  the  incisor, 
canine,  and  premolar  teeth  are  developing.  After  these  teeth 
are  erupted,  there  is  little  further  increase  in  the  length  of  this 


14  INTERNAL    ANATOMY    OF    THE    FACE. 

portion  of  the  jaw.  From  the  mental  foramen  to  the  ramus 
the  increase  is  inconsiderable  until  the  time  draws  near  for  the 
eruption  of  the  second  and  third  molars,  the  greatest  growth 
occurring  during  the  development  of  these  teeth,  and  gener- 
ally ceasing  after  the  eruption  of  the  last  named. 

The  contents  of  the  U-shaped  portion  grow  forward  as  the 
cortical  structure  increases  in  length,  the  teeth  immediately 
posterior  to  the  mental  foramen,  which  are  first  developed  in 
this  region,  being  pushed  forward  successively  by  each  de- 
veloping and  erupting  tooth.  It  is  this  forward  movement 
which  gives  the  curvature  to  the  various  small  tubes  to  the 
roots  of  the  teeth,  etc.,  and  accounts  for  the  stretching  of 
the  main  tube  until  its  distinctive  character  is  nearly  lost 
under  the  first  molar.  It  also  affords  a  rational  explanation 
of  the  recurrent  feature  of  the  tube  to  the  mental  foramen; 
the  end  of  this  tube  being  attached  to  the  wall  of  the  foramen, 
when  in  the  process  of  growth  the  mass  of  cancellated  tissue 
is  pushed  forward,  the  tube  itself  is  carried  along  with  it,  form- 
ing a  loop. 

The  reason  why  the  small  tubes  going  to  the  first  premolar 
and  the  canine  curve  backward  is,  that  their  points  of  origin 
have  been  carried  forward  with  the  return  tube  from  which 
they  spring.  The  small  tubes  going  to  the  incisors  curve 
slightly  forward,  as  they  arise  from  the  continuation  of  the 
main  tube  near  the  point  where  it  curves  backward  to  the 
foramen. 

Surgical  Significance.  This  anatomical  arrangement  has 
an  important  surgical  significance  in  certain  phases  of  the  op- 
eration of  resecting  the  inferior  dental  nerve,  for  if  the  general 
teaching  of  anatomy  be  followed  the  surgeon  is  liable  to  be 
misled.  If  the  operator  cuts  down  to  the  mental  foramen, 
then  seizes  the  mental  nerve  and  uses  it  as  a  guide  while  cut- 
ting the  bone  away  with  the  surgical  bur  from  the  posterior 
wall  of  the  foramen,  he  will  find  that  the  nerve  cannot  be  fol- 
lowed as  a  rule,  as  the  nerve  and  the  canal  do  not  pass  back- 
ward.    But  if  the  anterior  wall  be  cut  away,  then  the  nerve 


THE    MANDIBLE    OR    LOWER    JAW.  1 5 

can  be  followed  down  to  the  inferior  dental  nerve,  which  may 
then  be  uncovered  to  any  distance  deemed  necessary. 

Pathological  Significance.  The  pathological  significance 
of  this  bending  backward  of  the  nerve  and  its  bony  covering 
is  that  if  any  injury  be  received  in  this  region,  or  if  any  in- 
flammatory condition  be  produced,  either  traumatically  or  by 
infection  from  diseased  teeth,  the  nerve  is  liable  to  become  im- 
pinged upon  or  compressed,  thus  causing  pain  or  inflammation 
of  the  nerve  itself.  The  writer  has  found  neuromata  more 
common  in  this  region  than  at  any  other  portion  of  the  inferior 
dental  nerve,  probably  mainly  due  to  the  anatomical  condition 
under  consideration. 

Records  of  Development.  Thus  it  will  be  seen  that  the 
anatomical  structures,  the  relation  of  the  various  teeth  con- 
sidered with  regard  to  the  order  of  their  development,  and 
more  especially  the  direction  which  the  lateral  branches  of  the 
main  cribriform  tube  take  to  form  their  connection  with  the 
roots  of  the  several  teeth,  supply  us  with  permanent  records  of 
the  methods  of  growth  of  the  mandible  during  the  period 
between  childhood  and  adult  life. 

In  the  boiled  and  cleaned  specimen,  naturally  all  the  con- 
tents of  the  tubes — the  soft  tissues — have  disappeared;  but 
the  illustrations  (Figs.  4  and  5)  show  clearly  that  the  main  tube 
and  the  smaller  ones  passing  to  the  various  teeth,  and  the 
finer  tubes  going  to  the  interspaces  and  general  cancellated 
tissue,  have  the  same  general  direction  and  curvature  as  those 
going  to  the  roots  in  their  immediate  vicinity. 

Fig.  8  shows  a  specimen  from  which  the  soft  tissues  have 
not  been  removed.  It  shows  the  smaller  tubes  passing  to 
the  roots  of  the  teeth,  with  their  contents,  proving  that  these 
tubes  do  act  as  conduits  for  the  nerves  and  blood-vessels. 

Fig.  9  is  from  a  specimen  which  was  prepared  by  grinding 
away  the  labial  and  lingual  surfaces  of  the  bone  and  teeth 
until  the  pulp  chambers  and  apical  foramina  were  exposed  on 
both  sides  of  the  teeth,  leaving  the  tissues  extending  out  of 
the  foramina  and  through  a  portion  of  the  bony  cribriform 


i6 


INTERNAL   ANATOMY    OF   THE    FACE. 


tube  below.  In  one  tooth,  at  A,  the  lateral  wall  has  been 
broken  away,  leaving  the  tissues  uncovered  by  hard  struc- 
tures on  the  three  sides.  It  will  be  seen  that  the  nerve  has 
been  pushed  slightly  away  from  the  wall.  In  this  dissection 
and  in  many  others  it  will  be  observed  that  the  tissues  passing 


Fig.  8. 


View  of  mandible  (left  side),  with  the  cortical  portion  of  bone  removed  along  with 
the  cancellated  tissue,  exposing  the  nerves  and  vessels  within  the  cribriform  tubes  as 
they  pass-  to  the  roots  of  the  teeth. 


Fig.  g. 


Ground  section  of  the  six  anterior  teeth  and  two  left  premolars. 


into  the  teeth  give  off  small  branches  from  the  nerves  and 
vessels  just  below  the  apical  foramen.  So  clear  does  this  ap- 
pear that  the  writer  is  of  the  opinion  that  the  lower  portion  of 
the  pericementum  is  supplied  from  the  same  branches  of  the 
nerves  and  vessels  which  supply  the  pulp. 


THE    MANDIBLE    OR   LOWER   JAW. 


17 


Pathological  Significance.  The  pathological  significance  of 
this  condition  is  found  in  the  reciprocal  relation  of  pulp  hyper- 
emia and  congestion  with  the  same  conditions  affecting  the 


Fig.  10. 


Crystalline  Lens. 


Unciform  Process. 
Middle  Turbinate. 
Middle  Meatus. 
Maxillary  Sinus. 
Inferior  Meatus. 

Inferior  Turbinate. 


Vestibule  of  the  Mouth. 
First  Molar. 


Distal  Root  of  First  Molar. 


Inferior  Dental  Nerve. 


Anterior  view  of  vertical  transverse  bilateral  section  of  the  head,  shov^^ing  the  relations 
of  the  jaws  and  the  U-shaped  cortical  bone  of  the  mandible. 

apical  portion  of  the  peridental  membrane  so  frequently  ob- 
served in  clinical  practice. 

Fig.   10  is  a  vertical  transverse  section  through  the  jaws 
and  tongue  at  the  location  of  the  first  molars,  affording  a 


lO  INTERNAL    ANATOMY    OF    THE    FACE. 

good  idea  of  the  cortical  portion  of  the  bone  heretofore  re- 
ferred to,  of  its  relation  with  the  roots  of  the  teeth,  and  of  the 
position  of  the  cribriform  tube  with  the  nerve  for  which  it 
serves  as  a  conduit.  (For  further  description  of  this  illustra- 
tion see  Fig.  25,  page  37.) 

Fig.  II  is  a  view  of  the  anterior  portion  of  the  lower  jaw 
shown  in  Fig.  10.  The  roots  of  the  second  premolar,  it  will 
be  seen,  are  nearly  in  a  line  transversely  with  the  anterior 
roots  of  the  first  molar,  a  condition  which  is  not  at  all  uncom- 
mon.    As   the  premolar  roots   are  long  and   comparatively 

Fig.  II. 


Anterior  Root  of  First  Molar. 
Root  of  Second  Premolar. 

Inferior  Dental  Nerve. 
U-shaped  Cortical  Bone 


A  posterior  view  of  an  anterior  transverse   section   of     the   mandible   made  through 
the    anterior   first    molar,    showing   the    U  -shaped   cortical    bone. 


slender,  extending  below  the  roots  of  the  molar,  often  nearly 
to  the  inferior  dental  nerve,  while  the  bone  at  this  point  is 
usually  very  compact,  the  difficulty  occasionally  met  with  in 
extracting  these  teeth  without  breaking  them  is  readily  ac- 
counted for. 

Surgical  Pathology.  The  relation  of  these  roots  to  the 
cancellated  tissue  of  the  jaw  has  a  pathological  significance. 
If  their  pulps  become  diseased  and  infected,  the  infectious 
matter  may  pass  out  through  the  comparatively  open  tissue 
and  burrow  in  various  directions,  setting  up  an  osteomyelitis 
and  affecting  the  other  teeth,  eventually  causing  an  abscess, 
the  discharge  of  which  may  pass  either  through  the  mental 


THE    MANDIBLE   OR   LOWER   JAW.  I9 

foramen  or  through  the  alveolar  wall  into  the  mouth,  or  even 
through  the  main  portion  of  the  U-shaped  cortical  bone  into 
the  neck.  The  necrotic  process  thus  extended  may  include  in 
its  destructive  area  the  apical  regions  of  several  adjacent 
teeth,  causing  devitalization  of  their  pulps.  Some  practi- 
tioners inject  hydrogen  dioxid  through  the  teeth  into  ab- 
scesses of  this  character,  even  before  a  fistulous  opening  has 
formed.  The  decomposing  of  the  dioxid  in  contact  with  the 
pus  generates  gas  with  great  force.  If  this  gas  has  not  a  per- 
fectly free  outlet,  it  will  burrow  through  the  soft  tissues  and 
may  pass  along  the  cancellated  bone  from  one  end  of  the  jaw 
to  the  other.  The  writer  has  seen  cases  where  such  treatment 
has  resulted  in  the  formation  of  a  large  pathological  canal  ex- 
tending from  the  symphysis  menti  to  the  angle  of  the  jaw. 

Fig.  12  represents  the  left  side  of  a  lower  jaw  cut  lengthwise 
nearly  through  its  center,  exposing  the  cancellated  tissue,  the 
sockets  of  the  teeth,  and  the  cribriform  tube  or  inferior  dental 
canal,  with  its  branches  to  the  alveoli.  As  the  tissue  is  very 
frail,  a  considerable  quantity  of  the  trabecuke  was  lost  in  the 
cutting.  The  outer  section  shows  the  direction  of  the  re- 
current tube  for  the  accommodation  of  the  mental  nerve  and 
vessels. 

Fig.  13  represents  two  sides  of  a  metal  cast  showing  the 
cancellated  structure  within  the  U-shaped  portion  of  the  bone. 
It  was  made  in  the  following  manner,  from  a  perfect  and  thor- 
oughly cleaned  jaw  with  all  the  teeth  extracted.  After  cover- 
ing the  openings  of  the  sockets  of  the  teeth  with  paper,  the 
end  of  a  slender  tube  about  eighteen  inches  long  was  inserted 
in  the  inferior  dental  foramen.  The  bone  and  tube  were  then 
invested  in  plaster  of  Paris  mixed  with  a  little  asbestos.  After 
the  investment  was  thoroughly  set  and  dried,  it  was  heated  to 
about  212°  F.,  and  a  metal  of  low  fusibility  was  poured  into 
the  tube.  This  metal  passed  into  the  cribriform  tube  and 
along  its  course,  finding  its  way  out  through  the  many  open- 
ings into  the  cancellated  tissue  and  into  the  sockets  of  the 
removed  teeth.     After  the  plaster  investment  was  removed, 


20 


INTERNAL   ANATOMY    OF    THE    FACE. 


the  body  of  the  bone  and  the  lower  portion  of  the  ramus  were 
placed  in  a  lo  per  cent,  solution  of  potassium  hydroxid,  which 
dissolved  the  bone  away,  except  where  particles  of  the  can- 
cellated tissue  are  seen  as  white  spots  appearing  through  the 


Fig.  12. 


Longitudinal   division  of    a  mandible,   exposing    the  cancellated   tissues  in    the   body 
of  the  jaw  and  between  the  sockets  of  the  teeth. 


metal.     A  transverse  section  of  this  preparation  would  show 
fine  threads  of  bony  tissue  through  the  body  of  metal. 

A,  of  Fig.  13,  shows  the  inner  surface,  in  which  the  cast 
of  the  canal  or  tube  may  be  said  to  represent  the  space  occu- 
pied by  the  nerves,  blood-vessels,  and  their  membranes.  In  B, 
which   pictures   the  outer  surface,   the  dense  spot  near  the 


THE    MANDIBLE   OR   LOWER   JAW. 
Fig.   13. 


21 


Two  views  of  the  sides  of  a  metal  cast  of  the  open  spaces  in  the  body  of  the  mandible. 


22 


INTERNAL    ANATOMY    OF    THE    FACE. 


border    beneath    the    second    premolar    indicates    where    the 
nerves  and  vessels  passed  out  of  the  mental  foramen. 

Fig.  14  is  from  a  horizontal  section  of  the  upper  and  lower 
jaws,  a  little  beyond  the  free  margins  of  the  alveolar  processes. 


■S.nc^so^--^,^cV 


301:  • 


Fig.    14.         Ce^-^^^*    -ua^e'^'*  C*^^''"''' 


First  Premolar. 


First  Molar. 


Second  Premolar. 


First    Premolar. 


Horizontal  sections  of  the  upper  and  lower  jaws  cut  a  little  beyond  the  free  margin 
of  the  alveolar  process,  showing  the  forms  and  positions  of  the  roots  of  the  various 
teeth. 

It  shows  the  shape  and  position  of  the  various  roots  on  that 
plane,  and  their  relation  to  the  process  and  to  one  another. 
The   conditions  here   shown  are   so   common   as   to  warrant 


THE    MANDIBLE    OR    LOWER    JAW. 


23 


their  classification  as  the  normal  type.  Particular  attention  is 
drawn  to  the  slight  distance  between  the  roots  and  the  plates 
of  the  alveolar  process.  It  would  be  manifestly  impossible  to 
force  the  beaks  of  forceps  between  the  roots  and  the  alveolar 
process  in  such  cases  without  breaking  the  latter  on  one  or 
both  sides.  The  not  infrequent  splitting  off  of  a  section  of 
the  alveolar  process  in  extraction  is  thus  readily  accounted  for. 
The  lines  in  the  cut  represent  the  strongest  axes  in  the  teeth, 


Inferior 
Dental  Nerve. 

Roots  of 
Third  Molar. 


Roots  of 
Second  Molar. 

A  Root  of 
First  Molar. 


Root  of  Second 
Premolar. 

Root  of  First 
Premolar. 


Root   of   Canine. 


Root  of  Left  Lateral   Incisor. 


Horizontal  section  of  the  lower  jaw  cut  in  the  region  of  the  points  of  the  roots  of 
the  teeth. 

those  along  which  the  greatest  force  is  exerted  in  extracting 
operations,  and  which  are  usually  at  the  same  time  the  Hues  of 
least  resistance  of  the  surrounding  tissues. 

The  roots  of  the  teeth  extend  to  various  depths  in  the 
lower  jaw,  as  is  seen  in  Fig.  15,  which  represents  a  section  cut 
horizontally,  from  the  same  subject  as  Fig.  14,  though  nearer 
to  the  ends  of  the  roots.    The  ends  of  ihe  roots  of  the  second 


24  INTERNAL   ANATOMY    OF   THE    FACE. 

and  third  molars  are  plainly  seen,  also  the  tip  of  one  of  the 
roots  of  the  first  molar,  and  the  roots  of  the  first  and  second 
premolars.  A  little  of  the  lateral  incisors  will  be  noticed,  but 
the  centrals  do  not  go  down  so  far.  The  cancellated  portion, 
with  the  soft  tissue  filling  the  spaces,  is  well  shown  in  the 
posterior  portion  of  this  picture.  The  nerve  is  seen  passing 
into  its  tube. 

If  all  mandibles  with  their  teeth  were  like  those  just  de- 
scribed, surgery  of  the  lower  jaw  would  be  comparatively 
simple.  In  fact,  there  would  be  little  to  do  excepting  in  cases 
of  traumatism,  but  unfortunately  this  is  not  the  case,  as  will  be 
demonstrated. 

Inflammatory  Changes.  Inflammation  within  the  lower 
jaw  caused  by  "diseased  teeth,  or  by  constitutional  disturb- 
ances, may  completely  change  the  character  of  both  the  can- 
cellated and  cortical  portions,  by  stimulating  the  bone-build- 
ing cells  of  these  tissues  to  undue  activity.  Under  such  cir- 
cumstances, the  cancehated  tissue  may  be  filled  up  or  con- 
verted into  a  substance  so  nearly  resembling  the  cortical  bone 
that  the  line  of  demarkation  is  obliterated;  while  the  cortical 
portion  may  be  solidified — made  more  dense,  ivory-like — and 
thickened,  presenting  conditions  which  very  much  complicate 
the  situation  and  make  the  performance  of  operations  diffi- 
cult, and  sometimes  impracticable  by  the  usual  methods. 

Fig.  1 6  is  taken  from  a  section  made  transversely  through 
the  lower  jaw  at  the  mental  foramen  of  each  side.  On  the 
left  side  the  cortical  U-shaped  portion  and  the  cancellated  tis- 
sues are  about  normal  and  in  condition  similar  to  those  in 
Figs.  4  and  5,  while  on  the  right  side  the  cortical  portion  has 
thickened  and  become  dense,  and  the  cancellated  tissue  has 
become  filled  with  secondary  bone  deposit.  The  only  ap- 
parent reason  for  this  difference  is  that  all  the  teeth  on  the 
left  side  were  in  good  condition,  while  on  the  right  side  the 
first  molar  had  been  much  diseased,  causing  the  inflammation 
of  that  side  of  the  jaw;  vascular  excitement  induced  activity 
of  the  osteoblasts,  which  caused  the  deposit  of  secondary 
bone. 


TPIE    MANDIBLE    OR   LOWER   JAW. 


25 


Inflamed  conditions  in  the  jaws  of  children,  occasioned 
either  by  abscessing  teeth  or  by  constitutional  disturbances, 
will  cause  the  deposit  of  secondary  bo-ne  within  the  cancellated 
tissue,  binding  it  to  the  U-shaped  cortical  portion.  In  such 
cases,  when  the  time  for  the  eruption  of  the  molars  arrives, 
especially  of  the  second  and  third,  it  is  impossible  for  the  can- 
cellated tissue  and  the  erupting  teeth  to  glide  forward  as 
shown  in  Fig.  5.  Many  cases  of  the  impaction  of  the  third 
molar  are  doubtless  due  to  the  existence  of  such  conditions. 

Fig.  16. 


Transverse  division  of  a  mandible  at  the  mental  foramina.  The  left  side  .is  in  an 
almost  normal  condition,  while  on  the  right  side  the  cortical  bone  has  thickened  and 
become  dense,  and  the  cancellated  tissue  has  become  filled  with  secondary  bone  deposit. 

Surgical  Pathology.  The  normal  and  pathological  anat- 
omy of  the  two  sides  of  the  jaw  shown  in  Fig,  16  would  re- 
quire different  modes  of  surgical  procedure.  The  teeth  on 
the  right  side,  being  placed  in  an  unyielding  bone,  would 
fracture  in  an  attempted  extraction,  and  the  roots  would  re- 
main in  the  jaw.  The  cutting  of  the  bone  down  to  the  inferior 
dental  canal  and  nerve  on  the  left  side  in  a  case  of  this  char- 
acter would  also  be  quite  a  dififerent  operation  from  a  similar 
operation  on  the  right  side.  The  first  would  be  done  with 
ease,  the  other  with  difficulty,  and  when  the  cutting  was  done 


26  INTERNAL    ANATOMY    OF    THE    FACE. 

it  would  be  difficult  to  find  and  remove  the  nerve.  Correc- 
tion of  irregularities  of  the  teeth  in  the  consolidated  area 
would  be  almost  impossible. 

Necrosis  and  Regeneration.  If  certain  portions  of  bone  be^ 
lost,  either  by  necrosis  or  even  by  surgical  operation,  under 
favorable  conditions  some  new  bone  will  be  formed. 

In  the  lower  jaw  the  regeneration  of  bone  is  more  likely 
to  occur  than  in  the  upper.  After  removal  of  a  section  of  the 
jaw  regeneration  of  bone  commonly  takes  place,  and  if  the 
stumps  are  held  in  position  and  the  space  is  not  too  great,  a 
natural  bridge  is  formed  between  them,  especially  if  portions 
of  the  periosteum  are  left. 

Neuralgia.  Secondary  bone  deposit  in  the  cortical  and 
cancellated  tissue  of  the  face  is  an  important  factor  in  pro- 
ducing facial  neuralgia,  as  branches  of  the  trifacial  nerve  pass 
through  not  only  to  the  bone  itself,  but  also  to  the  region 
beyond  in  various  directions.  In  the  left  side  of  Fig.  i6  the 
spaces  are  comparatively  open,  while  the  right  side  of  the 
same  jaw  is  nearly  soHd;  nerves  passing  through  this  half 
would  be  impinged  upon,  and  neuralgia,  the  cause  of  which 
would  be  difficult  to  determine,  would  result.  In  neuralgia 
from  this  cause,  the  obvious  treatment  would  be  the  burring 
away  of  the  greater  part  of  the  abnormally  solidified  bone, 
using  the  surgical  engine,  a  much  better  agent  for  its  removal 
than  the  ordinary  mallet  and  chisel. 

Secondary  Deposits.  The  cancellated  portion  of  the  mandible 
usually  increases  in  compactness  as  persons  advance  in  years. 
Along  with  the  progressive  increase  in  density  of  the  tissues 
due  to  advancing  years,  other  factors,  pathological  in  char- 
acter, by  which  the  teeth  become  diseased,  set  up  an  inflam- 
matory condition,  which  causes  secondary  deposits. 

Fig.  17  shows  several  sections  from  a  lower  jaw,  which  was 
not  quite  normal,  there  being  evidence  of  past  inflammation 
having  changed  the  structure  of  the  bone.  Several  teeth  had 
been  extracted  before  death.  In  some  of  the  sections  only 
one  canal  is  seen,  while  in  others  several  appear,  necessitating 


THE    MANDIBLE    OR    LOWER    JAW. 


27 


close  observation  to  decide  into  which  the  main  nerves  and 
vessels  have  passed. 

In  the  resection  or  removal  of  the  entire  nerve  from  the 
bone,  a  surgeon  not  anticipating  this  condition  might  easily 
clear  out  a  portion  of  a  canal  without  touching  the  main 
nerve.     This  mistake  might  not  occur  in  the  dry  bone,  but 


Fig.  17. 


•"'I 
,1' 


i 


Sections  made  at  different  points  from  a  mandible  which  was  not  quite  normal  in  its 
density. 

in  the  living,  where  the  parts  are  vascular,  the  error  could 
easily  be  made.  In  section  D  it  will  be  seen  that  the  anterior 
root  of  the  second  molar  penetrates  the  true  nerve  canal.  In 
case  of  abscess  of  this  root,  the  discharge  would  flow  into  the 
nerve  canal,  thence  backward  or  forward  along  the  nerve, 
causing  great  pain  by  compression. 

Fig.   18  represents  a  specimen  in  which  the  roots  of  the 


28  INTERNAL   ANATOMY    OF   THE    FACE. 

third  molar  passed  out  through  the  inner  wall  of  the  lower 
jaw,  at  a  considerable  distance  below  the  mylo-hyoid  ridge. 
A  putrescent  pulp  in  this  tooth  would  have  discharged  its  in- 
fective matter  at  once  into  the  submaxillary  triangle.  The. 
writer  believes  that  there  are  many  serious  unrecognized  caF^es 
where  devitalized  teeth  of  this  character  cause  infection  o[  the 
tissues  of  the  neck,  and  even  of  the  thoracic  cavity.  Therefore, 
if  diseased  teeth  in  this  region  do  not  respond  to  t,-eatment 

Fig.  i8. 


Part  of  a  mandible  showing  the  roots  of  the  third  molar  tooth  passing  through  the 
inner  wall  into  the  submaxillary  fossa. 

at  once,  they  should  be  extracted,  as  not  only  ill  health,  but 
death  itself  may  and  does  occur  from  their  presence.  The 
writer  has  seen  large  triangular  swellings  just  under  the  jaw, 
which  indicated  that  there  was  trouble  within  the  submax- 
illary triangle,  a  symptom  of  an  enlarged  submaxillary  gland. 
Upon  examination  of  the  teeth  a  diseased  molar  was  found, 
and  after  this  tooth  was  removed  the  swelling  subsided. 

Mandibular  Triangle.  A  marked  variation  of  the  lower  jaw 
is  found  in  the  relative  distances  between  the  centers  of  the 
two    condyles  and  between   these  and  the   central  incisors. 


THE    MANDIBLE   OR   LOWER    JAW. 


29 


These  measurements  have  been  commonly  accepted  as  de- 
scribing an  equilateral  triangle.  The  measurements  of  the 
jaws  which  have  passed  through  the  writer's  hands  do  not 
bear  out  this  hypothesis.  In  fact,  the  variations  are  as  great 
as  in  any  other  feature  of  the  face.  In  only  one  case  was  an 
exact  equilateral  triangle  found.  Some  approached  that  fig- 
ure, but  in  the  great  majority  the  sides  of  the  triangle,  taking 
the  distance  between  the  centers  of  the  two  condyles  as  the 
base,  considerably  exceeded  the  length  of  the  base.  In  rare  in- 
stances the  base  exceeded  the  length  of  the  sides.    The  varia- 


FiG.  ig. 


Fig.  20. 


Two   mandibles   showing  variations  in   distance   between   the  two   condyles  and  from 
the  condyles  to  the  incisor  teeth. 


tions  here  noted  would  seem  to  indicate  that  while  the  equi- 
lateral triangle  may  be  assumed  as  a  general  basic  principle 
in  the  architecture  of  the  lower  jaw,  the  variations  are  the 
anatomical  facts  with  which  we  are  practically  concerned  so 
long  as  the  hypothetical  form  remains  unproved. 

Figs.  19  and  20  are  made  from  photographs  of  two  jaws 
in  which  rather  extreme  conditions  were  found.  In  Fig.  19 
the  base  of  the  triangle  is  nearly  one-third  shorter  than  either 
of  the  sides.  In  Fig.  20  the  base  exceeds  either  side.  Be- 
tween these  extremes  (and  probably  to  some  extent  beyond 
them  on  either  side)  every  variation  in  the  relation  of  the  sides 
to  the  base  of  the  triangle  may  be  found  in  normal  jaws. 


30  INTERNAL   ANATOMY    OF   THE    FACE. 

In  this  description  of  the  lower  jaw  or  mandible,  the  inten- 
tion has  been  to  emphasize  the  necessity  for  the  surgeon  to 
promptly  recognize  departures  from  the  accepted  diagram- 
matic form  of  the  normal  jaw,  and  the  results  of  pathologi- 
cal changes  in  its  structures.  The  attempt  has  been  to  illus- 
trate this  necessity  by  typical  cases  which  should  serve  to 
enforce  principles  rather  than  enter  into  details. 


THE    MAXILLA    OR    UPPER    JAW.  ;^  I 


THE  MAXILLA  OR  UPPER  JAW. 


The  upper  jaw,  from  a  surgical  point  of  view,  includes  the 
right  and  left  maxillae,  and  in  addition  all  the  other  facial 
bones  except  the  mandible  and  part  of  the  ethmoid  and 
sphenoid  bones  of  the  cranium.  The  surgical  operation  of 
removing  the  right  or  left  maxilla  does  not  usually  involve 
the  removal  of  the  entire  bone,  for  the  nasal  process,  the 
floor  of  the  orbit,  and  the  zygomatic  surface  may  be  left. 
In  its  removal,  however,  the  inferior  turbinate,  portions  of 
the  lachiymal,  the  palatal,  the  malar,  and  the  ethmoid  bones 
will  probably  be  removed  with  it.  Especially  is  this  true  in  the 
general  method  of  operating,  but  if  the  resections  are  made 
with  the  assistance  of  the  surgical  engine,  the  greater  portion 
of  the  associated  bones  may  be  left  undisturbed. 

Architectural  Features.  The  maxillae  are  situated  beneath 
the  walls  of  the  anterior  fossae  of  the  brain-case  and  rather 
loosely  attached  by  what  may  be  termed  buttresses  and  flying- 
buttresses.  In  the  center,  near  the  nasion,  the  nasal  processes 
rest  firmly  against  a  buttress  in  the  median  line,  the  internal 
angular  processes  of  the  frontal  bone.  Below  is  a  flying  but- 
tress, the  nasal  septum,  especially  that  portion  formed  by  the 
vomer,  which  passes  upward  and  backward  from  the  inter- 
articulating  ridge  of  the  maxillse  and  palate  bones  to  the 
buttress-like  body  of  the  sphenoid  bone,  where  it  is  firmly 
held  or  braced  in  place  by  the  vaginal  processes.  Laterally 
the  upper  jaw  is  supported  through  the  malar  bones  by  the 
external  angular  processes  of  the  frontal  bone  and  the  flying- 
buttresses  of  the  zygomatic  arches  to  the  temporal  bones  at 


32  INTERNAL   ANATOMY   OF   THE    FACE. 

the  sides  of  the  skull;  posteriorly  by  the  pterygoid  process  of 
the  sphenoid,  with  a  portion  of  the  palate  bone  interposed. 

The  buttresses,  situated  and  distributed  as  they  are,  not 
only  afford  support  against  forces  acting  externally,  but  also 
dissipate  and  diffuse  shocks  which  would  otherwise  be  trans- 
mitted to  the  cranium.  As  a  consequence  of  its  construction, 
but  little  force  in  a  forward  direction  is  necessary  to  detach 
the  upper  jaw  from  the  cranium,  though  it  will  withstand  a 
blow  of  great  force  received  from  below  through  the  lower 
jaw  or  from  in  front,  or  even  from  the  side. 

Pathological  Relations.  The  upper  jaw  gives  support  to 
one-half  of  the  teeth  and  like  the  lower  jaw  is  subject  to  de- 
fects of  development  and  to  various  pathological  changes, 
chief  among  which  may  be  mentioned  cleft  palate,  congenital 
or  acquired;  necrosis,  caries,  sarcoma,  odontoma,  odontocele, 
impacted  and  supernumerary  teeth.  It  may  also  be  affected 
by  alveolar  and  dento-alveolar  abscesses,  diseases  of  the 
mucous-lined  sinuses  and  air  spaces,  which  last  may  also  give 
rise  to  such  symptoms  as  impaired  respiration  and  the  dis- 
charge of  offensive  matter.  Tumors  or  abscesses  of  the  max- 
illary sinus  often  grow  to  such  a  size  as  to  elevate  the  floor  of 
the  orbit,  depress  the  roof  of  the  mouth,  and  force  outward 
the  waHs  of  the  cavity,  distorting  the  contour  of  the  face  in 
the  region  of  the  canine  fossae.  Neuralgia  in  the  teeth  may  be 
symptomatic  of  disease  of  the  bones  of  the  jaw,  and  neuralgia 
in  many  regions  of  the  head  is  traceable  to  the  teeth. 

The  under  surface  of  the  upper  jaw  is  bounded  by  the  alveo- 
lar process  and  the  roof  of  the  mouth  or  the  palatal  processes, 
both  of  which  are  covered  by  periosteum  and  mucous  mem- 
brane (muco-periosteum).  That  portion  of  the  mucous  mem- 
brane over  the  alveolar  process  is  thick  and  dense,  and  is 
known  as  gum-tissue;  it  contains  but  few  mucous  glands, 
while  the  portion  covering  the  roof  of  the  mouth  is  not  so 
dense  and  is  well  supplied  with  racemose  mucous  glands. 

The  Alveolar  Process.  The  alveolar  process  is  made  up 
of  two  plates,  an  external  and  an  internal,  consisting  of  dense. 


THE    MAXILLA    OR    UPPER    JAW. 


33 


compact,  cortical  bone.  The  outer  plate  extends  upward  and 
merges,  without  a  line  of  demarkation,  into  the  outer  surface 
of  the  true  maxilla.  The  inner  plate  extends  upward  and 
inward  and  is  continuous  with  the  palatal  process  of  the  palate 
bone  and  maxilla  proper.  The  space  between  the  plates  is 
occupied  by  the  sockets  of  the  teeth,  the  alveoli,  which  are 
surrounded  by  a  very  thin  cribriform  plate  of  bone,  by  cancel- 

Fig.  21. 


View  of  the  under  surface  of  the  upper  jaw  showing  the  alveoli  of  the  various  teeth. 


lated  tissue,  nerves,  vessels,  etc.  The  alveolar  process  belongs 
to  the  teeth  and  is  developed  with  them  for  the  purpose  of 
holding  them  in  position.  It  disappears  in  various  degrees 
after  the  teeth  are  lost,  sometimes  before,  more  especially 
when  there  is  pyorrhea  alveolaris,  and  also  as  an  indication  of 
advancing  old  age.  Should  the  alveolar  process  be  the  pri- 
mary seat  of  disease,  sound  teeth  will  loosen  and  may  fall  out. 
The  outer  alveolar  plate  is  resorbed  after  the  loss  of  the  teeth 

3 


34 


INTERNAL    ANATOMY    OF    THE    FACE. 


to  a  greater  extent  than  the  inner  one,  which  is  of  advantage 
to  the  dentist  in  fitting  artificial  teeth  to  the  gums;  conse- 
quently, in  extracting  teeth  this  fact  should  be  remembered, 
so  that  injury  to  the  internal  plate  may  be  avoided.  At  the 
same  time,  no  particular  harm  results  from  the  removal  of  a 
small  portion  of  the  outer  plate,  though  the  loss  of  any  of  the 
gum-tissue  should  be  avoided  if  possible. 

Fig.  22. 


GLABELLA 


ANTERIOR    NASAL^    , 
SPINE  \--- 


PROSTHION. 


GNATHION 


J^ja' MASTOID 
'''llONION 


Side  view  of  a  typical  skull. 

Fig.  21  gives  a  fair  idea  of  the  alveoli  of  the  upper  jaw.  It 
will  be  observed  that  there  are  two  sockets  for  the  roots  of 
the  second  premolar  teeth.  This  is  not  usual,  though  it  oc- 
curs occasionally.  On  the  right  side  there  are  spaces  for  five 
roots  for  the  third  molar,  which  also  is  not  common. 

In  order  to  thoroughly  appreciate  the  differences  in  the 
bony  anatomy  of  the  face,  it  is  necessary  to  study  skulls  and 
bones  considered  typical  at  various  periods  of  life. 


THE    MAXILLA    OR    UPPER    JAW. 


35 


Fig.  22  gives  a  side  view  of  an  almost  ideal  skull,  with  its 
perfect  occlusion  of  the  teeth,  and  with  the  various  bony  parts 
indicated  according  to  the  received  modern  nomenclature. 

Fig.  23  represents  a  front  view  of  the  same  skull.  It  is 
nearly  symmetrical,  presenting  the  typical  anatomy  of  the 
external    bony    structures    of    the    face.      There    is    but    the 

Fig.  23. 


Anterior  view  of  the  typical  skull  shown  in  Fig.  22. 

slightest  variation  in  the  two  sides.  It  will  be  noticed  that  the 
upper  right  first  molar  stands  out  slightly  more  than  the  left. 
The  septum  of  the  nose  is  seen  to  be  deflected  in  the  same 
direction,  and  upon  examination  of  the  internal  structures  of 
the  nose  it  is  found  that  the  bulla  ethmoidaHs  is  enlarged  on 
the  left  side,  projecting  toward  the  concavity  in  the  septum. 
This  is  an  example  of  what  might  be  taken  as  quite  a  constant 
anatomical    law,   that  when   the   mouth,   palate,   and   dental 


36 


INTERNAL    ANATOMY    OF    THE    FACE. 


arches  are  bilaterally  symmetrical,  the  outer  cranial  struc- 
tures exhibit  a  like  condition.  What  is  more,  this  bilateral 
symmetry  will  be  found  to  extend  throughout  the  body. 
However,  this  law,  as  well  as  all  others  relating  to  anatomical 
science,  has  its  exceptions. 

Fig.  2a. 


Under  view  of  the  skull  shown  in  Figs.  22  and  23,  with  the  mandible  removed. 


Fig.  24  shows  a  view  of  the  same  skull  from  below,  where 
it  still  appears  almost  perfect  anatomically.  The  slight  pro- 
jection of  the  upper  right  first  molar  is  again  observable,  and 
it  will  also  be  seen  that  the  external  plates  of  the  pterygoid 
processes  are  not  quite  alike  on  both  sides;  there  is  also  a 
slight  difference  in  the  zygomatic  arches. 

Fig.  25*  shows  a  transverse  bilateral  section,  passing  verti- 

*Fig.  25  is  a  repetition  of  Fig.  10. 


THE    MAXILLA    OR    UPPER    JAW. 


37 


cally  through  the  anterior  portion  of  the  orbit,  the  maxillary 
sinus,  and  the  first  molar  of  each  jaw,  dividing  the  eye  just  in 
front    of    the    crystalline    lens.      In    the    upper    portions    of 

Fig.  25. 


Crystalline  Lens. 


/     1 
"V  J       mi  ^^iT^  Unciform  Process. 
/  •  'd^BS~  Middle  Turbinate. 
Middle  Meatus. 
Maxillary  Sinus. 
Inferior  Meatus. 

Inferior  Turbinate. 


Vestibule  of  the  Mouth. 
First  Molar. 


Distal  Root  of  First  Molar. 


Inferior  Dental  Nerve. 


Anterior   view    of    a   vertical    transverse    bilateral    section   of    the    head,    showing   the 
relations  of  the  jaws,  and  indicating  the  pcjsitions   of  the  turbinates,   antra,   etc. 

the  nasal  cavities  are  seen  the  middle  ethmoidal  cells.  At 
about  the  center  of  the  floor  of  the  orbit  and  the  roof  of  the 
sinus,  which  is  very  thin  in  this  case,  will  be  found  the  infra- 
orbital canal  as  commonly  described,  and  below,  the  nearly 


38  INTERNAL    ANATOMY    OF    THE    FACE. 

pyramidal  cavity  of  the  maxillary  sinus,  with  a  partial  septum 
crossing  transversely  from  the  inner  to  the  outer  wall. 

In  the  lower  angle  of  the  left  sinus  can  be  seen  the  anterior 
buccal  root  of  the  second  molar,  while  on  the  inner  wall  is  a 
portion  of  the  palatal  root  of  the  first  molar.  The  palatal  root 
of  the  right  first  molar  is  easily  seen  passing  well  up  in  the 
inner  wall  of  the  sinus. 

The  central  portions  of  Figs.  25  and  26  afford  excellent 
views  of  transverse  sections  of  the  nasal  chamber.  The  sep- 
tum in  the  center  is  unusually  straight.  Above  the  septum 
is  the  crista  galli,  to  which  the  falx  cerebri  is  attached  an- 
teriorly. On  each  side  of  the  septum,  at  the  upper  attach- 
ment, is  the  roof  of  the  nasal  chamber.  Running  down  on 
either  side  at  a  little  distance  from  this  are  the  middle  turbi- 
nate bones,  the  scroll-shaped  bones  below,  and,  hanging 
from  the  outer  wall,  the  inferior  turbinate  bones.  The  su- 
perior turbinate  bones  cannot  be  seen  in  a  section  cut  in  this 
region,  as  they  are  situated  further  back  in  the  skull. 

Fig.  26  represents  the  anterior  portion  of  the  same  skull 
shown  in  Fig.  25.  At  the  anterior  superior  angle  of  the 
antrum  is  seen  a  cord  marking  the  passage  (ostium  maxillare) 
from  the  antrum  into  the  hiatus  semilunaris.  In  the  floor  of 
the  antrum  will  be  seen  the  septum  referred  to  in  the  descrip- 
tion of  Fig.  25.  On  the  left  side  will  be  observed  the  palatal 
and  anterior  buccal  roots  of  the  first  molar  in  the  outer  and 
inner  walls  of  the  antrum.  The  positions  of  these  roots,  as 
shown  here  and  in  Fig.  25,  are  very  interesting  from  a  dental 
standpoint.  The  extraction  of  teeth  having  roots  in  such 
positions,  if  not  carefully  done,  might  carry  away  parts  of  the 
floor  of  the  sinus  (see  Fig.  58),  or  in  case  of  breakage  in  ex- 
tracting, the  roots  could  easily  be  forced  into  the  sinus  by  in- 
judicious use  of  the  forceps.  Also,  by  using  too  much  force 
in  placing  artificial  crowns,  the  floor  might  be  fractured. 

In  the  majority  of  the  skulls  belonging  to  the  white  race  so 
far  examined,  roots  of  the  molar  teeth  pass  up  into  the  walls  of 
the  antrum,  being  covered  at  the  point  where  they  approach 
the  surface  by  only  a  thin  conical  portion  of  bone. 


THE    MAXILLA    OR    UPPER    JAW 


39 


Fig-.  27  shows  a  section  similar  in  character  to  Figs.  25  and 
26,  but  from  a  negro  skull.  Note  the  great  thickness  of  the 
floor  of  the  antrum,  and  the  position  of  the  roots  of  the  teeth. 
In  the  negro  race  the  walls  and  the  floor  are  much  thicker 
than  in  the  white;  therefore,  as  a  rule,  the  roots  of  the  teeth  do 
not  pass  up  into  the  wall,  or  even  near  the  floor  of  the  sinus. 

Fig.  26. 


First  Molar 


First  Molar. 


Posterior  view  of  vertical  transverse  bilateral  section  of  the  head  from  the  same 
skull  as  Fig.  25,  shoviJing  the  ostium  maxillare,  which  is  indicated  on  each  side  by  a 
cord  passed  through  it. 


Fig.  28  is  an  illustration  of  a  tooth  which  has  been  perfo- 
rated by  a  drill  wdiile  in  the  mouth,  the  operator  supposing  his 
drill  was  passing  up  the  palatal  root,  instead  of  which  it  passed 
through  the  pulp  chamber,  the  base  of  the  crown,  the  alveolar 
process,  and  into  the  maxillary  sinus.  It  will  be  observed 
that  in  extracting  it  a  portion  of  the  floor  of  the  antrum  has 
been  brought  away  with  the  tooth.  At  the  time  of  extraction 
the  patient  was  suffering  from  empyema  of  the  antrum. 


40 


internal  anatomy  of  the  face. 
Fig.  27. 


Anterior  view   of  a  vertical   transverse   bilateral   section  of  a   negro  skull,   showing  a 
deep   alveolar  process. 

Fig.  28. 


Tooth  which  has  been  drilled  through  while  in  the  mouth. 

Fig.  29  is  taken  from  the  skull  of  a  child  of  about  six  years, 
showing  all  the  deciduous  teeth  in  position  and  the  developing 
permanent  teeth,  except  the  third  molar  of  the  lower  jaw  and 


THE    MAXILLA   OR    UPPER    JAW. 


41 


the  second  and  third  upper  molars,  which  at  this  period  of 
life  are  in  a  very  immature  state.  The  outer  plate  of  the  alveo- 
lar process  and  the  cancellated  tissue  have  been  removed, 
in  order  that  the  positions  and  relations  of  the  dental  organs 
at  this  period  of  life  may  be  more  clearly  seen. 

Fig.  29. 


Skull  of  a  child  about  six  years  old,  showing  all  the  deciduous  teeth  in  position  and 
the  developing  permanent  ones. 


Fig.  30*  gives  an  antero-lateral  view  of  an  almost  ideal 
articulation  of  the  permanent  teeth.  The  illustration  shows 
the  relation  of  the  bones  forming  the  external  structures  of 
the  jaws.  The  outer  surfaces  of  the  lateral  and  anterior  walls 
of  the  antrum  are  shown,  the  teeth  having  been  denuded  of 
the  external  plate  of  the  alveolar  process.  It  will  be  seen  that 
in  removing  the  external  plate  the  maxillary  sinus  has  been 
opened  into  immediately  over  the  roots  of  the  molars,  showing 


*Fig.   30  is  a  repetition  of   Fig.  4. 


42 


INTERNAL    ANATOMY    OF    THE    FACE. 


how  thin,  in  this  case,  the  bone  is  between  the  roots  of  the 
teeth  and  the  external  wall  of  the  sinus.  It  is  also  very  thin 
over  the  roots  of  the  canine  and  first  and  second  premolars. 

Fig.  30. 


Antero-lateral  view  of  upper  and  lower  jaws  with  the  external  plates  of  the  alveolar 
process  and  some  of  the  cancellated  tissue  removed,  exposing  the  roots  of  the  teeth 
and   the  cribriform  tubes. 

The  infraorbital  foramen  is  the  termination  of  the  infraor- 
bital canal,  which  is  generally  described  as  passing  through  the 
solid  bone  of  the  infraorbital  ridge  to  the  groove  in  the  floor 
of  the  orbit.    As  a  matter  of  fact,  this  canal  often  passes  diag- 


THE    MAXILLA    OR    UPPER   JAW.  43 

onally  through  the  maxillary  sinus,  somewhat  in  the  form  of  a 
tube.* 

At  the  inner  anterior  angle  of  the  floor  of  the  orbit  will  be 
observed  the  opening  of  the  nasal  duct,  which  will  be  again  re- 
ferred to  when  viewing  the  internal  structures  of  the  maxillary 
sinus  and  the  nasal  fossae.  The  lower  jaw  of  this  figure  has 
been  described.     (See  Fig.  4.) 

Figs.  5,  14,  and  30  demonstrate  the  arrangement  of  the  can- 
cellated tissue  between  the  teeth,  also  between  the  teeth  and 
the  cortical  bone,  where  it  acts  as  an  elastic  cushion  to  lessen 
shock  from  blows  upon  the  lower  jaw  or  from  concussion  in 
mastication.  It  is  this  arrangement  which  permits  the  move- 
ment of  the  teeth  in  various  directions  during  eruption  or 
in  correcting  irregularities  of  the  teeth. 

Nutritional  Supply  to  the  Teeth.  The  vessels  of  nourish- 
ment of  the  posterior  teeth  of  the  upper  jaw  do  not  pass 
through  and  along  the  cancellated  tissue  as  they  do  in  the 
lower  jaw,  but  in  a  groove  on  the  outer  wall  of  the  maxillary 
sinus  (as  shown  in  B,  Fig.  31),  from  which  are  given  off 
branches  to  the  apices  of  the  roots  of  the  teeth,  many  of  the 
latter  being  covered  with  only  a  thin  plate  of  bone.  Occasion- 
ally this  thin  covering  is  lacking.  The  upper  anterior  teeth 
are  supplied  by  branches  or  continuations  of  the  posterior 
dental  nerve  and  vessels,  passing  through  canals  or  tubes  in 
the  cancellated  portion  of  the  bone. 

The  principal  nerves  and  vessels  supplying  these  teeth  are 
smaller  than  those  for  the  lower  teeth,  because  they  are  not 
required  to  give  off  large  external  branches,  as  the  mental 
branches  to  the  lower  lip  and  adjacent  tissue.  They  pass  to 
the  upper  teeth  along  shallow  grooves  in  the  walls  of  the 
maxillary  sinus  (see  B,  Fig.  31).  The  length  of  these  grooves 
varies  considerably,  depending  somewhat  on  the  distance  from 
the  main  branch  to  the  portion  over  the  roots  of  the  teeth. 

In  some  teeth  where  the  roots  are  imbedded  in  the  inner 

*For  further  description  of  this  variation,  see  page  63. 


44 


INTERNAL   ANATOMY    OF    THE    FACE. 

Fig.  31. 


Anterior  Dental  Cana 


Alveolar  Process. 
A 


Groove  for  Superior  Den 

tal  Nerve  and  \^essels.        ^''^i- 


Sound  passed  through    Infraor- 
bital Canal  and  Foramen. 


Antero-posterior    division    through    the    maxillary    sinus    and    the    teeth,    showing    an 
infraorbital  sinus  above  the  canal. 


THE    MAXILLA    OR    UPPER    JAW.  45 

plate  of  the  bone  forming  the  antrum,  the  nerve  and  vessel 
pass  at  once  into  the  apical  foramen.  If  they  pass  through 
the  cortical  bone,  they  will  only  be  found  in  a  short  canal;  but 
where  their  course  is  through  cancellated  tissue  to  the  apical 
foramen,  as  in  the  case  of  the  anterior  teeth,  or  through  other 
surrounding  tissue,  they  are  conveyed  in  tubes  more  or  less 
cribriform  in  character,  somewhat  similar  to  those  found  in  the 
lower  jaw. 


46  INTERNAL    ANATOMY    OF    THE    FACE. 


THE  NASAL  FOSS^. 


Descriptive  Anatomy.  The  nasal  fossae — the  internal  nose 
— are  two  chambers  situated  on  each  side  of  the  median  line 
of  the  face,  extending  downward  from  the  under  surface  of 
the  anterior  portion  of  the  brain-case  superiorly,  to  the  upper 
surface  of  the  bones  forming  the  hard  palate  inferiorly,  and 
from  the  facial  border  to  the  external  aperture  of  the  nose 
anteriorly  to  the  free  border  of  the  external  pterygoid  plate 
posteriorly.  They  are  lined  with  muco-periosteum  covered 
with  ciliated  epithelium;  and  the  membrane  is  continuous  with 
the  hning  of  the  several  sinuses,  cells,  and  passageways  of  this 
region.  On  the  upper,  lateral,  and  posterior  borders  of  the 
nasal  fossae  there  are  various  mucosa-lined  sinuses,  cells,  and 
canals,  all  communicating  with  the  fossae,  the  excess  of  fluids 
secreted  by  them  passing  into  the  nose.  The  lachrymal  ducts 
conveying  the  excess  of  fluids  from  the  anterior  surface  of  the 
eyes,  the  Eustachian  tubes  communicating  with  the  middle 
ear,  and  the  maxillary  sinus,  the  frontal  sinus,  the  sphenoidal 
sinus,  the  ethmoidal  cells,  and  the  cells  belonging  to  the  or- 
bital process  of  the  palate  bone,  have  their  outlets  in  the  nasal 
fossae.  The  fossae  are  separated  from  each  other  by  a  thin 
partition  of  bone  and  cartilage,  the  nasal  septum;  they  open 
on  the  anterior  surface  by  the  anterior  nares.  The  two  prin- 
cipal functions  of  the  nose  of  man  are  concerned  with  the  be- 
ginning of  the  respiratory  act  and  with  the  special  sense  of 
olfaction. 

The  lower  part  of  the  chamber  forms  a  direct  passageway 
for  the  air  into  the  respiratory  tract,  also  for  the  expired  air 
leaving  the  lungs.  The  upper  portion  of  that  part  of  the 
fossae  formed  by  the  ethmoid  bone  contains  the  beginning  of 


THE    NASAL    FOSS.^.  47 

the  olfactory  organs.  As  it  is  necessary  to  their  function 
that  these  parts  be  kept  moist,  there  are  numerous  pockets 
in  and  about  them  the  hning  membrane  of  which  secretes 
fluids.  These  fluids  pass  over  the  shed-hke  projections  of  the 
turbinate  bones  into  the  nose,  supplying  the  necessary  mois- 
ture. 

In  Figs.  25  and  26  are  good  examples  of  nasal  fossae  of 
bilateral  symmetry.  For  convenience  in  describing  the  nasal 
fossa,  it  may  be  divided  into  roof,  floor,  and  outer  and  inner 
walls,  the  last  named  being  formed  by  the  nasal  septum. 

The  roof  of  the  nasal  fossa  is  long,  narrow,  and  irregular  in 
form.  It  is  divided  into  anterior,  middle,  and  posterior  sec- 
tions. 

The  anterior  portion  is  formed  by  the  under  surface  of  the 
nasal  bones  and  the  nasal  spine  of  the  frontal  bone.  It  is 
concave  from  side  to  side,  and  extends  inward  and  upward  to 
the  ethmoid  bone,  at  an  angle  of  about  forty-five  degrees. 

The  middle  portion  is  narrow,  nearly  horizontal  in  direction, 
and  is  composed  of  the  under  surface  of  the  cribriform  plate 
of  the  ethmoid  bone,  through  the  openings  of  which  the  fila- 
ments of  the  olfactory  nerves  pass  between  the  nasal  fossae 
and  the  brain.  Besides  the  numerous  openings  there  are  slit- 
like foramina,  which  give  passage  to  the  nasal  ner^^es  and 
vessels.  The  cribriform  plate,  on  account  of  its  thinness  and 
its  sieve-like  construction,  and  the  presence  of  the  slit-like 
openings,  affords  but  a  slight  partition  between  the  nasal 
chamber  and  the  anterior  portion  of  the  brain-case. 

The  posterior  portion  of  the  roof  of  the  nose  is  the  longest 
of  the  three  parts,  and  extends  from  the  posterior  extremity 
of  the  cribriform  plate  obliquely  downward  and  backward  to 
the  free  margin  of  the  internal  pterygoid  plate.  It  is  com- 
posed of  the  body  of  the  sphenoid  bone  and  the  alae  of  the 
vomer. 

The  floor  of  the  nasal  chamber  extends  from  the  external 
opening  anteriorly  to  the  pharyngeal  space  posteriorly.  It  is 
smooth,  and  concave  from  side  to  side.     The  bonv  structure 


48  INTERNAL    ANATOMY    OF    THE    FACE. 

is  composed,  anteriorly  of  the  intermaxilla,  medially  of  the 
palate  processes  of  the  maxilke,  and  posteriorly  of  the  horizon- 
tal plate  of  the  palate  bone.  The  nostril,  the  anterior  open- 
ing, is  made  up  of  cartilage  and  is  lined  with  mucous  mem- 
brane. The  cartilaginous  portion  forms  the  vestibule  of  the 
nose.  In  the  normal  nose,  the  floor  joins  this  on  the  same 
plane  and  gradually  slopes  downward  and  backward.  (See 
Fig.  32.)  Occasionally  there  is  quite  a  depression  immediately 
back  of  the  union  of  the  bone  and  cartilage.  The  floor  often 
varies  in  its  relative  position  to  the  other  structures.  It  is 
seldom  on  the  same  level  as  the  floor  of  the  antrum;  it  may 
be  on  either  a  higher  or  a  lower  plane.  Examples  of  these 
variations  are  seen  in  the  sections  shown  in  Figs.  66,  67,  68,. 
and  69. 

The  nasal  septum  forms  the  inner  walls  of  the  nasal  fossae. 
It  consists  of  six  bony  structures,  named  in  the  order  of  their 
importance, — viz.,  the  vertical  plate  of  the  ethmoid,  the  vomer, 
the  crests  of  the  maxillae  and  palate  bones,  the  rostrum  of 
the  sphenoid,  and  the  nasal  spine  of  the  frontal  bone.  These 
bones  do  not  form  the  septum  completely,  but  leave  a  tri- 
angular notch  in  the  anterior  portion,  which  is  filled  up  with 
cartilage. 

Septal  Spurs.  In  Figs.  25  and  26  it  will  be  seen  that  the 
nasal  septum  is  nearly  vertical,  without  a  bend  or  a  nodular 
process  or  "spur"  upon  it.  It  is  commonly  thought  by  rhi- 
nologists  that  a  straight  septum  is  unusual.  This  would  seem 
to  be  an  error,  probably  due  to  the  fact  that  the  great  ma- 
jority of  the  noses  which  they  examine  are  abnormal.  It  is 
quite  true  that  in  many  cases  the  septum  is  more  or  less  de- 
flected or  curved  to  one  side  or  the  other,  assuming  a  central 
position  only  as  it  passes  downward  and  nears  its  connection 
with  the  floor  of  the  chamber.  On  the  convex  side  of  the 
curve  in  these  cases,  a  ridge  or  process  is  often  found  which  is 
called  a  "spur,"  and  which  may  extend  quite  over  and  come  in 
contact  with  the  external  wall  or  the  inferior  turbinate.  (See 
Figs.  67,  82,  and  90.) 


THE    NASAL    FOSS^.  49 

Nasal  Meati.  The  external  lateral  wall  is  the  most  extended, 
irregular,  and  complicated  portion  of  the  nasal  fossa.  It  varies, 
perhaps,  more  in  its  general  formation  than  any  other  portion 
of  the  body  of  like  size,  and  is  correspondingly  difficult  to 
treat  surgically.  Several  bones  enter  into  its  formation  on 
each  side, — viz.,  the  nasal,  maxihary,  lachrymal,  ethmoid,  in- 
ferior turbinated  and  palate  bones,  the  pterygoid  process,  and 
the  body  of  the  sphenoid  bone.  By  the  projection  of  the  in- 
ferior turbinated  bones  and  processes  of  the  ethmoid  bone, 
this  wall  is  divided  into  several  almost  horizontal  compart- 
ments known  as  meati.  The  anatomical  works  generally  name 
three  meati, — the  inferior,  the  middle,  and  the  superior. 
Zuckerkandl,  however,  says  that  about  6^^  per  cent,  of  the 
skulls  examined  by  him  have  had  four  meati.  The  writer  has 
found  about  sixty  per  cent,  with  four  meati  in  the  skulls  of 
which  he  has  made  sections.  (See  A,  Fig.  33,  and  Fig.  84.) 
In  many  cases  there  are  five,  and  in  one  skull  were  found  six. 

Figs.  32  and  33  give  a  general  idea  of  the  arrangement  of 
the  outer  walls  of  the  nasal  chambers.  The  upper  portion,  or 
all  of  that  which  belongs  to  the  ethmoid  bone,  is  associated 
with  olfaction.  The  ends  of  the  nerves,  usually  called  the  ter- 
minals, have  their  origin  over  this  region;  they  also  are  dis- 
tributed over  the  upper  portion  of  the  septum  and  the  roof  of 
the  nose.  The  fibers  converge  as  they  pass  upward  to  form 
the  filaments,  and  then  through  the  various  foramina  in  the 
cribriform  plate  of  the  ethmoid  bone  enter  the  olfactory 
bulb.  The  various  meati  have  communications  with  the  max- 
illary sinus  and  other  air  spaces  which  are  formed  in  the  bones 
of  this  region. 

Inferior  Meatus.  The  inferior  meatus  is  situated  between 
the  inferior  turbinated  bone  and  the  floor  of  the  nose.  It  is 
much  longer  than  the  others  and  is  the  principal  passageway 
of  respiration. 

Nasal  Canals.  The  nasal  canals,  which  are  for  the  accom- 
modation of  the  lachrymal  ducts,  have  their  origin  in  the 
inner  anterior  lower  angle  of  the  orbits.     The  superior  ori- 

4 


50 


INTERNAL    z\NATOMY    OF    THE    FACE. 


fices  commence  between  the  nasal  processes  of  the  maxilte 
and  the  lachrymal' bone.  From  this  point  the  canals  extend 
down   and    terminate   in    the   upper   portion    of   the    inferior 

Fig.  32. 


Right  Frontal  Sinus. 


Left    Frontal    Sinus. 


Superior  Turbinate. 

Superior   Meatus. 
Middle  Turbinate. 

.Middle  Meatus. 


Inferior   Turbinate. 
Inferior  Meatus. 


Hard  Palate. 


Alveolar    Process. 


External  wall  of  a  left  nasal  fossa. 


meatus  of  the  nose.  (See  Figs.  34,  35,  37,  38,  and  39.)  The 
direction  of  their  descent  varies  considerably  in  different  sub- 
jects, and  even  in  the  same  subject.  They  usually  pass  back- 
ward, and  when  the  antrum  is  large  and  the  nasal  chamber 


THE    NASAL    FOSS^. 

Fig.  3.3. 


51 


A  B 

External  walls  of  the  nasal  chamber,  each  showing  four  meati. 

Fig.  34. 


—  Frontal  Sinus. 


Middle  Turbinate. 

Ostium  Maxillare. 

Middle  Meatus. 

Posterior  Half  of 
Lachrymal  Duct. 

Inferior  Turbinate. 


Inferior  Meatus. 


Internal  Wall  of  Maxillary  Sinus. 


Anterior  view  of  a  vertical  transverse  section  of  the  right  side  of  face. 


52 


INTERNAL    ANATOMY    OF    THE    FACE. 


narrow,  the  direction  may  be  inward;  where  the  antrum  is 

smaU  and  the  nasal  fossa  wide,  the  direction  is  Hkely  to  be 

outward.     In   exceptional   cases   it   is   slightly   curved.     The 

duct  may  have  a  valve  composed  of  mucous  membrane  at  its 

lower  extremity. 

Fig.  35. 


I  rental   Sinus 


Nasal   Chamber. 
Nasal    Septum. 


Inferior  Turbinate, 
Inferior   Meatus. 


.^^  Anterior  Half  of  Lachrymal 
,- Malar  Bone.  [^uct. 


f^r,  ^£_  Anterior  Wall  of  Maxillary 
[Sinus. 


Hard  Palate.        Alveolar   Process. 
Posterior  view  of  a  vertical   section  cut  from  the  front  of  Fig.   34. 

Fig.  34  affords  an  anterior  view  of  a  section  cut  vertically 
or  longitudinally  through  the  lachrymal  duct,  showing  its  pos- 
terior portion  as  it  passes  from  the  orbit  downward  within 
the  wall  separating  the  nasal  chamber  from  the  maxillary 
sinus,  the  duct  terminating  in  the  upper  portion  of  the  infe- 


THE    NASAL    FOSS.E.  53 

rior  meatus.  On  the  upper  right  corner  is  the  h^ontal  sinus. 
To  the  left  of  this  is  the  orbit.  In  the  center  of  the  waU  be- 
tween the  orbit  and  the  maxillary  sinus  will  be  seen  the  infra- 
orbital canal,  and  below  it  the  maxillary  sinus,  which  in 
this  case  is  very  large.  In  the  upper  portion  of  the  nasal 
chamber  is  seen  the  middle  turbinated  bone,  below  which  is 
seen  a  cord  which  has  been  passed  from  the  middle  meatus 
through  the  ostium  maxillare  into  the  maxillary  sinus. 

Fig.  35  is  from  a  vertical  section,  cut  transversely  just 
within  the  infraorbital  ridge.  In  the  upper  portion  is  the 
anterior  wall  of  the  frontal  sinus,  on  the  left  side  is  the  nasal 
septum,  and  to  the  right  of  this  is  the  nasal  cavity.  The  an- 
terior half  of  the  nasal  duct,  shown  in  the  previous  illustra- 
tion, will  be  seen  to  commence  at  the  inner  angle  of  the  orbit 
and  terminate  at  the  inferior  meatus. 

Fig.  36  is  from  a  section  near  the  posterior  wall  of  the 
antrum  and  the  orbits,  from  the  same  subject  as  Figs.  34  and 
35.  It  will  be  noticed  that  the  wall  of  the  antrum  is  very 
thin.  At  the  upper  right  corner  are  seen  the  posterior  eth- 
moidal cells,  below  which  is  the  nasal  chamber. 

Fig.  37  is  from  a  section  showing  the  greater  portion  of  the 
upper  jaw.  The  upper  boundary  is  on  a  level  with  the  middle 
of  the  orbits.  Two  sounds  passed  down  into  the  lachrymal 
ducts  indicate  that  the  ducts  pass  outwardly  as  they  descend 
into  the  upper  part  of  the  inferior  meatus.  It  will  be  ob- 
served that  the  right  duct  has  a  greater  outward  deflection 
than  the  left.  (The  impacted  canine  tooth  will  be  referred  to 
when  impacted  teeth  are  considered, — see  page  127.) 

The  horizontal  line  above  the  roots  of  the  teeth  and  below 
the  malar  bone  makes  a  division  of  the  section  just  above  the 
floor  of  the  nasal  chamber.  The  under  surface  of  the  upper 
portion  is  shown  in  Fig.  38,  which  affords  a  view  of  the  surface 
of  the  inferior  turbinate  from  below,  with  the  lower  orifices 
of  the  lachrymal  duct.  It  also  shows  the  lower  edges  of  the 
middle  and  superior  turbinates,  and  the  roofs  of  the  antra. 
Attached  to  the  roof  of  the  right  maxillary  sinus  are  two  ab- 
normal bony  growths  generally  known  as  osteophytes. 


54 


INTERNAL   ANATOMY    OF   THE    FACE. 


The  middle  meatus  is  situated  between  the  lower  portion 
of  the  turbinate  masses  of  the  ethmoid  bone  and  the  inferior 
turbinate,  and  forms  two-thirds  of  the  posterior  portion  of  the 
outer  wah  of  the  nasal  fossa.     This  is  the  most  important 

Fig.  s6. 


Maxillary  Sinus. 


Posterior  Ethmoidal  Cells. 
Orbit. 


Middle   Meatus. 
Middle  Turbinate. 

Nasal   Septum. 
Inferior  Turbinate. 

Inferior  Meatus. 


Alveolar    Process. 
Anterior  view  of  vertical  section  cut  posterior  to  that  shown  in  Fig.  34. 


meatus  and  is  subject  to  more  variations  in  its  anatomy,  physi- 
ology, and  pathology  than  are  all  the  others.  It  has  anatomi- 
cal communications  with  the  frontal  and  maxillary  sinuses,  and 
with  the  anterior  and  middle  ethmoidal  cells.  In  order  to 
study  this  meatus  and  its  relations,  it  is  necessary  to  make  a 


THE    NASAL    FOSS^. 


55 


number  of  sections  of  the  parts  with  aU  the  tissues  in  place. 
By  removing  the  middle  turbinate,  the  internal  structure  of 
the  parts  is  brought  into  view. 

Fig.  39  shows  the  outer  wall  of  the  nasal  chamber  with  the 
internal  wall  of  the  turbinate  mass  of  the  ethmoid  bone  cut 
loose  and  turned  up,  affording  a  good  idea  of  the  normal 
anatomy  of  this  region.  The  frontal  sinuses  are  exposed. 
In  the  illustration  the  right  frontal  sinus  extends  over  the 


Section  showing  the  greater  portion  of  the  upper  jaw.  S  S,  sounds  passed  down 
lachrymal  duct,  showing  that  they  do  not  pass  at  the  same  angle.  The  illustration  also 
shows   an  impacted   canine  tooth. 

left  side  of  the  median  line.  The  open  space  immediately 
below  this  is  the  left  frontal  sinus.  The  partition  between 
these  sinuses  in  some  places  is  thin.  The  lower  portion  of  the 
left  frontal  sinus  is  funnel-shaped.  This  opens  into  a  passage 
leading  into  the  middle  meatus,  the  funnel-shaped  portion  and 
the  passage  being  commonly  called  the  infundibulum. 

Hiatus  Semilunaris.  The  infundibulum  is  often  included 
in  the  part  which  has  been  named  by  Zuckerkandl  the  hiatus 
semilunaris,  and  which  extends  from  the  frontal  sinus  to  and 


56 


INTERNAL    ANATOMY    OF    THE    FACE. 


through  the  middle  meatus  in  the  form  of  a  semicircular 
groove  or  cleft  along  the  outer  wall  of  the  meatus.  It  ex- 
tends downward  and  backward  in  a  curved  direction,  being 
horizontal  in  its  posterior  portion,  and  terminates  a  little  be- 

FlG.  38. 


Osteophytes 


H         ^ 


Horizontal  section  showing  the  under  surfaces  of  the  inferior  turbinates  and  the  outlet 
of  the  lachrymal  duct. 


hind  the  center  of  the  nasal  cavity.  At  its  commencement  it 
is  narrow,  but  it  widens  as  it  passes  downward  and  backward, 
its  widest  part  being  at  the  bottom  and  near  the  opening  be- 
tween  the   maxillary   sinus   and  the   nasal   chamber   (ostium 


THE    NASAL    FOSS.T,. 


57 


maxillare).  Besides  the  opening-  of  the  frontal  sinus  into  the 
hiatus  semilunaris,  there  are  openings  from  the  anterior  and 
middle  ethmoidal  cells,  and  from  the  maxillarv  sinus.     Its  in- 


FiG.  39. 

Section    lurncd  Up 


Right  Frontal  Sinus. 


Left  Frontal  Sinus. 


Infundibulum. 


Anterior  Ethmoidal 
Cells. 

^  Hiatus  Semilunaris. 

r"  Unciform  Process. 


Middle   Meatus. 


Inferior  Turbinate. 
Probe  passing  into 
Lachrymal  Duct. 

Inferior   Meatus. 


Hard  Palate. 


Alveolar  Process. 


An    antero-posterior    section    within    the    nasal    chamber,    with    the    middle    turbinate 
bone  and  portion  of  cell  walls  turned  up. 

ner  boundary  is  falciform  in  shape,  and  is  composed  of  the 
uncinate  process  of  the  ethmoid  bone  with  membranous  tis- 
sue, forming  a  shield  or  guard  to  the  opening  of  the  maxillary 
sinus,  to  prevent  foreign  substances  from  passing  into  it.     A 


5©  INTERNAL    ANATOMY    OF    THE    FACE. 

"sound"  cannot  be  passed  from  the  nasal  chamber  through  the 
ostium  maxillare  into  the  maxillary  sinus  In  a  normal  living 
person. 

The  superior  meatus  is  shallow,  and  is  shorter  than  the 
inferior  or  middle  meatus.  It  is  situated  between  the  superior 
and  inferior  turbinate  masses  of  the  ethmoid  bone,  and  in 
the  articulated  skull  between  the  superior  and  middle  turbi- 
nates. The  cell  situated  in  the  orbital  process  of  the  palate 
bone,  the  posterior  ethmoidal  cells,  and  the  sphenoidal  sinus 
all  have  their  openings  into  this  meatus  when  there  are  but 
three  meati,  but  when  there  are  four  the  posterior  ethmoidal 
cells  and  the  sphenoidal  sinus  have  their  openings  into  the 
fourth  or  supreme  meatus.  If  there  are  five  meati  the  sphe- 
noidal sinus  usually  opens  into  the  fifth.  In  other  words,  this 
sinus  has  a  tendency  to  open  into  the  highest  meatus. 

The  fourth  or  supreme  meatus  of  Zuckerkandl  is  formed 
by  an  infolding  of  a  portion  of  the  turbinate  mass  similar  to 
that  of  the  third  or  superior  meatus,  though  smaller  in  extent. 
When  the  fourth  meatus  exists,  the  fluids  of  the  posterior 
ethmoidal  cells  and  those  from  the  sphenoidal  sinus  pass 
through  it  to  reach  the  nasal  chamber. 

The  occasional  fifth  meatus  is  formed  similarly  to  the  third 
and  fourth  meati  by  an  infolding  of  the  upper  portion  of  the 
turbinate  mass.  In  such  cases  the  fluids  from  the  sphenoidal 
sinus  pass  through  it  instead  of  into  the  fourth. 


THE    MAXILLARY    SINUS.  59 


THE  MAXILLARY   SINUS. 


The  maxillary  sinus  (antrum  of  Highmore)  is  the  largest 
air  cavity  associated  with  the  nasal  chamber.  It  is  situ- 
ated in  the  body  of  the  maxilla  on  each  side.  It  varies  in 
shape,  size,  and  in  the  thickness  of  its  walls,  according  to  age, 
race,  and  the  presence  or  absence  of  teeth  and  tooth-germs 
within  the  jaw.  It  is  lined  with  muco-periosteum  surmounted 
by  cihated  epithelium.  The  typical  sinus  is  pyramidal  in 
shape,  the  apex  being  toward  the  malar  bone, — into  which  it 
may  extend  (see  Fig.  76), — and  the  base  toward  the  nasal 
cavity.  Its  size  and  form  vary  in  different  subjects,  and  even 
in  the  two  sides  of  the  same  subject.  (See  Figs.  65,  68,  69,  70, 
and  71.)     In  rare  cases,  it  is  lacking  on  one  or  both  sides. 

Fig.  40  is  a  view  of  the  skull  of  a  fully  developed  embryo 
from  the  collection  of  Professor  Thomas  C.  Stellwagen.  It  is 
a  transverse  section  cut  vertically  just  within  the  floor  of  the 
orbit.  In  the  upper  portion  are  seen  two  openings  into  the 
brain-case  with  the  crista  galli  and  falx  cerebri  between  them, 
below  which  is  the  nasal  chamber  with  its  septum.  Project- 
ing from  the  outer  wall  of  the  chamber  are  the  middle  and 
inferior  turbinates.  In  the  middle  meatus  may  be  seen  the 
unciform  process  passing  upward  and  a  little  inward  from  the 
base  of  the  inferior  turbinate.  At  the  outer  side  of  this  is  the 
passageway  known  as  the  hiatus  semilunaris,  from  which  there 
is  a  small  opening  (ostium  maxillare)  passing  into  the  max- 
illary sinus,  which  is  very  small  at  this  period  of  embryonic 
life. 

The  development  of  the  sinus  begins  about  the  fourth 
month  of  gestation  by  an  invagination  of  the  lining  membrane 
of  the  nose  from  the  hiatus  semilunaris  into  the  body  of  the 


6o 


INTERNAL    ANATOMY    OF    THE    FACE. 


maxilla.  From  the  time  of  the  invagination  until  the  eruption 
of  the  permanent  teeth,  the  greater  portion  of  the  maxilla  is 
occupied  by  the  dental  organs.  (See  Fig.  29.)  As  the  invagi- 
nation progresses,  the  cancellated  portion  of  the  bone  under- 
goes resorption.  This  resorption  of  the  internal  portion  of  the 
maxilla  is  continued  in  a  variable  degree  throughout  life,  until 

Fig.  40. 


y 


Anterior   Fossa 
of  Brain-Case. 
Crista  Galli. 

—  Orbit. 

—  Nasal  Septum. 

'  Ostium  Maxillare. 
Maxillary  Sinus. 
Malar  Bone. 
Maxilla. 

|>  Dental    Germs. 
Mandible. 


Hard  Palate. 


Skull    of   a   fully    developed    embryo    cut   vertically   through    the   first    deciduous    pre- 
molars. 


in  old  age  the  walls  usually  become  exceedingly  thin,  as  shown 
in  Fig.  43.  In  some  cases  the  decalcification  and  resorption  are 
carried  to  such  an  extent  that  the  entire  bone  is  thinned,  and 
an  ordinary  lancet  blade  can  be  easily  passed  through  the 
wall  into  the  sinus,  or  the  entire  substance  of  the  bone  may 
be  resorbed  in  places,  leaving  nothing  but  the  muco-perios- 


THE   MAXILLARY   SINUS.  6l 

teum  at  these  points.  As  this  process  goes  on,  the  roots  of 
the  premolars  and  molars  within  the  walls  are  approached, 
until  in  many  places  the  points  of  the  roots  are  covered  only 
by  a  thin  lamina  of  bone.  (See  Fig.  41.)  Even  this,  in  rare 
cases,  may  be  lost,  leaving  only  the  muco-periosteum  as  a  root- 
covering. 

At  first  the  sinus  has  a  sphenoidal  shape,  but  it  eventually 
approaches  the  pyramidal  form.  Its  walls  are  five  in  number, 
the  inferior  or  floor,  the  anterior  or  facial,  the  posterior  or 
zygomatic,  the  superior  or  roof,  and  the  proximal  or  nasal. 

The  floor  of  the  maxillary  sinus  is  somewhat  triangular 
in  its  general  outhne,  and  is  usually  uneven,  owing  to  the 
presence  of  partial  septa  and  conical  elevations  over  the  roots 
of  the  various  teeth.  These  elevations  are  found  over  the 
roots  of  the  molars,  sometimes  over  those  of  the  premolars, 
and  less  frequently  over  those  of  the  canine  teeth.  As  age 
advances  and  the  teeth  underlying  the  sinus  are  lost,  the  floor 
becomes  comparatively  smooth.  Septa  may  extend  to  various 
heights  transversely  from  side  to  side,  forming  deep  pockets 
between  them.  The  floor  of  the  antrum  may  descend  between 
the  roots  of  the  molar  teeth,  as  shown  in  Figs.  25  and  26,  a 
condition  much  more  common  among  the  white  race  than 
among  negroes.  In  the  negro  skull  these  elevations  over 
the  roots  of  the  teeth  are  seldom  found  because  of  the  greater 
thickness  of  the  bone,  so  that  the  floor  of  the  sinus  in  the  negro 
is  usually  smooth.  The  floor  is  concave  from  side  to  side  and 
slightly  so  in  the  antero-posterior  direction,  as  shown  in  Figs. 
27,  34,  and  60,  having  thus  a  basin-like  form,  and  is  usually 
below  the  level  of  the  nasal  chamber.     (See  Figs.  27  and  34.) 

The  anterior  wall  is  almost  a  square  with  rounded  corners. 
It  is  smooth,  with  a  slight  depression,  which  varies  according 
to  the  position  of  the  passage  of  the  infraorbital  canal  or  tube, 
as  shown  in  Fig.  31.  Occasionally  the  roots  of  the  canine 
and  premolar  teeth  are  found  in  this  wall.  In  infancy  it  con- 
tains the  follicles  of  the  anterior  teeth.  (See  Fig.  29.)  The 
anterior  dental  canal  for  the  accommodation  of  the  anterior 


62  INTERNAL   ANATOMY    OF    THE    FACE. 

■dental  nerves  and  vessels  passes  from  the  sinus  into  the  wall 
to  reach  the  anterior  teeth.  (See  Fig.  31.)  The  reason  why 
this  canal  is  so  high  up  in  the  bone  is  that  the  apices  of  the 
roots  of  the  teeth,  more  especially  of  the  canines,  before  erup- 
tion or  during  development  and  growth,  are  situated  high  up 
in  the  bone.  As  the  teeth  descend  to  their  position  in  the 
arch,  the  nerves  and  vessels  are  extended  and  the  bony  tissue 
closes  around  them,  leaving  for  their  accommodation  a  canal 
along  the  track  traveled  by  the  teeth. 

The  outer  wall  of  the  sinus  is  more  or  less  triangular  and 
concave  on  its  inner  surface;  the  concavity  may  extend  into 
the  malar  bone.  (See  Fig.  76.)  The  wall  also  extends  upward 
and  outward  in  a  slightly  curved  manner,  though  it  varies 
somewhat  according  to  the  position  of  the  section.  The  sur- 
face may  be  broken  up  over  the  buccal  roots  of  the  teeth,  as 
shown  in  B,  Fig.  41.  The  plate  of  bone  forming  the  outer  wall 
varies  in  thickness  and  density  and  undergoes  changes  in  this 
particular  at  different  periods  of  life.  In  childhood  the  dental 
organs  of  the  upper  jaw,  before  eruption,  are  located,  in  whole 
or  in  part,  in  the  outer  or  anterior  wall  or  in  the  floor  of  the 
sinus.  Fig.  29  shows  the  relation  of  the  first  or  deciduous  teeth 
to  the  floor  of  the  antrum  at  the  location  of  the  molars.  A 
little  later,  as  the  development  of  the  permanent  teeth  pro- 
ceeds and  they  are  pushed  forward  preparatory  to  taking  their 
place  in  the  arch,  the  outer  and  lower  portion  of  the  maxillary 
bone  appears  to  be  crowded  with  teeth,  as  shown  in  Fig.  29. 

The  posterior  or  zygomatic  wall  extends  from  a  line  ver- 
tical to  the  center  of  the  malar  process  backward  and  inward 
to  the  proximal  or  nasal  wall.  It  is  concave  in  a  transverse 
direction  and  nearly  straight  in  its  vertical  direction.  In  the 
young  it  is  thick,  but,  like  the  outer  wall  of  the  antrum,  it  be- 
comes thinner  and  thinner  as  age  advances,  until  it  may  be 
no  thicker  than  a  sheet  of  note-paper. 

The  superior  wall  or  roof  of  the  sinus  is  usually  triangular 
in  shape,  the  base  of  the  triangle  beginning  at  the  inner  or 
nasal  wall.   It  is  convex  in  a  transverse  direction,  with  the  inner 


THE   MAXILLARY   SINUS.  63 

edges  varying  in  height.  Its  junction  with  the  inner  waU  varies 
in  position  in  different  subjects.  Sometimes  it  is  found  on  the 
level  of  the  center  of  the  floor  of  the  orbit.  (See  B,  Fig.  79.) 
At  other  times  it  is  higher  and  near  the  center  of  the  inner  or- 
bital wall.  (See  Figs  73  and  94.)  Its  surface  is  usually  marked 
by  a  ridge  of  bone  which  contains  the  canal  for  the  passage  of 
the  infraorbital  vessels  and  nerves.  This  canal  commences  at 
the  posterior  border  of  the  floor  of  the  orbit;  continuing  for- 
ward, it  is  lost  about  the  middle  of  the  floor,  where  it  passes 
into  the  infraorbital  foramen.  The  ridge  extends  downward 
and  forward  to  meet  the  anterior  wall  of  the  sinus,  as  shown 
in  Figs.  31,  54,  79,  and  141.  The  dipping  down  of  the  ridge 
varies  greatly  in  extent,  being  scarcely  noticeable  in  some 
specimens,  while  in  others  it  extends  downward  so  far  that  the 
canal  becomes  distinctly  tubular  in  character,  passing  diago- 
nally through  the  sinus,  carrying  the  infraorbital  nerves  and 
vessels  across  the  anterior  portion,  with  an  open  space  above 
the  tube.  (See  Figs.  31,  54,  79,  and  141.)  The  open  space 
above  the  antrum  extends  outward  into  the  lower  rim  of 
the  orbit,  forming  an  infraorbital  sinus  or  pocket,  as  seen  in 
Figs.  31,  54,  79,  92,  and  141,  a  variation  which  the  writer  has 
not  seen  mentioned  in  any  work  on  anatomy.  The  tube-like 
canal  has  a  thin  lamina  of  bone  extending  from  it  to  the  side 
of  the  true  sinus. 

The  proximal  or  nasal  wall  of  the  sinus  is  quadrangular  in 
shape,  with  the  inferior  angles  slightly  rounded.  (See  Figs. 
42  and  85.)  In  a  typical  skull  this  wall  is  vertical  and  slightly 
convex.  The  lower  edge  almost  always  turns  slightly  outward 
to  join  the  floor  of  the  sinus,  but  occasionally  it  is  found  dip- 
ping in  under  the  floor  of  the  nasal  chamber  toward  the 
median  line,  and  meeting  the  floor  of  the  sinus  over  the  pala- 
tine process.     (See  Figs.  66,  B  of  83,  and  94.) 

The  ostium  maxillare,  an  oval-shaped  foramen,  which  af- 
fords communication  between  the  sinus  and  the  nasal  fossa 
through  the  hiatus  semilunaris,  is  usually  found  on  the  upper 
edge  of  the  proximal  wall  near  the  anterior  portion.      It  occa- 


64 


INTERNAL    ANATOMY    OF    THE    FACE. 


sioiially  commences  in  the  roof  of  the  sinus,  then  passes  in  a 
sHghtly  curved  direction,  terminating  in  the  hiatus  semi- 
lunaris, as  shown  in  Fig.  B,  79,  and  Figs.  81  and  85.  In 
pathological  conditions  or  in  extreme  old  age,  there  may  be 
two  or  even  more  openings  between  the  maxillary  sinus  and 
the  nasal  chaml)er.     (See  Figs.  95,  96,  and  97.) 

Septa  of  the  Maxillary  Sinus.      The  shape  and  size  of  the 
maxillary  sinus  and  the  character  of  its  septa  vary  so  much 

Fig.  41. 


B 

Two  antcro-posterior  sections  made  by  dividing  the  orbit  and  maxillary  sinus  verti- 
cally, showing  conical  elevations  over  the  roots  of  the  various  teeth.  The  root  of  the 
second   premolar  curves   forward.     It   more   commonly  curves   backward. 


that  it  is  almost  impossible  to  say  what  is  typical  shape  and 
what  are  typical  septa.  From  whatever  direction  sections  are 
made,  variations  in  shape  and  size  will  be  found.  Partial  bony 
or  membranous  septa  are  found  passing  partly  across  in  various 
directions,  but  the  writer  has  been  unable  to  find  complete 
septa  of  the  maxillary  sinus,  though  it  is  said  by  some  in- 
vestigators that  they  exist. 


THE   MAXILLARY  SINUS. 


65 


Fig.  42  represents  an  antero-posterior  section  near  the 
inner  wall  of  the  orbit,  showing  a  maxillary  sinus  of  about  the 
average  size  for  the  age  of  the  subject.  A  portion  of  the  os 
planum  is  cut  away  to  show  the  continuation  of  the  outlet  of 

Fig.  42. 


Antero-posterior    division    tliruiiKli    the    maxillary    sinus. 

the  sinus.     A  partial  bony  septum  arising  from  the  floor  and 
passing  transversely  across  forms  two  deep  pockets. 

Fig.  43  shows  vertical  membranous  septa  of  differing  sizes 
on  the  two  sides,  dividing  the  lower  portion  of  the  cavity  into 
semi-chambers.     The  septum  on  the  left  side  is  small;  that  on 

5 


66  internal  anatomy  of  the  face. 

Fig.  43. 


Anterior  view  of  a  vertical  transverse  section  from  a  skull  of  an  old  person,  showing 
the  thinness  of  the  walls  of  the  maxillary  sinus,  also  membranous  septa  of  the  sinus. 


Fig.  44. 


Osteophytes  on  the  Sept 


Foramen  between  External 
Internal  Chambers  of  Sinu 


Membranous  Septum  of  Sinus. 

A  vertical  antero-posterior  division  through  the  frontal   sinus,   orbit,   and  maxillary 
sinus,  showing  a  membranous  septum  of  the  sinus. 


THE   MAXILLARY   SINUS.  O/ 

the  right  extends  nearly  to  the  roof.     Resorption  has  reduced 
the  thickness  of  the  walls  of  the  antrum  to  thin  bony  layers. 

Fig.  44  is  from  an  antero-posterior  section  through  the 
frontal  sinus,  the  middle  of  the  orbit,  and  the  maxillary  sinus, 
showing  an  incomplete  vertical  antero-posterior  membranous 
septum  with  a  foramen  connecting  the  external  and  internal 
compartments  of  the  sinus.  Situated  on  the  membrane  are  a 
number  of  small  osteophytes. 

Fig.  45. 


A  B 

Antero-posterior  division  through  the  center  of  the  orbit,  maxillary  sinus,  and  molar 
teeth,  showing  a  crescent-shaped  cell  at  the  upper  posterior  corner  of  the  maxillary 
sinus. 


Fig.  45  shows  what  might  be  thought  to  be  a  bony  division 
■of  the  maxillary  sinus;  but  close  investigation  reveals  that  the 
crescent-shaped  cavities  situated  on  the  upper  posterior  corner 
of  the  sinus  are  the  cell  of  the  orbital  process  of  the  palate 
bone  cut  in  two.  A  probe  passed  through  the  opening  in  B 
would  enter  the  superior  meatus  of  the  nose. 

Fig.  46  shows  a  section  of  a  negro  skull  through  the  molar 
teeth  and  the  middle  of  the  orbit.  It  shows  a  sinus  at  the 
upper  posterior  corner  of  the  maxillary  sinus.    This  opens  into 


68 


INTERNAL   ANATOMY    01--    THE    FACE. 


the  superior  meatus  of  the  nose  and  belongs  to  the  palate 
bone.     The  antrum  is  very  small. 

Fig.  46. 


Antero-posterior  division  through  the  center  of  the  orbit,  maxillary  sinus,  and  molar 
teeth,  showing  a  triangular  cell  at  the  upper  posterior  corner  of  the  maxillary  sinus. 

Fig.  47. 


/^>  ~y 


Ff.-- 


Antero-posterior  division  through  the  center  of  the  orbit,  maxillary  sinus,  and  molar 
teeth,  showing  a  peculiarly  shaped  sinus. 


Fig.  47  is  taken  from  the  left  side  of  another  negro  skull. 
The  section  is  made  in  the  same  region  as  the  last,  showing  a 


THE   MAXILLARY  SINUS. 


69 


very  small,  peculiarly  shaped  antrum,  and  a  crescent-shaped 
cell  which  opens  into  the  superior  meatus. 

Fig.  48  is  from  the  right  side  of  the  same  skull  as  Fig.  47, 
showing  apparently  two  sinuses.  The  posterior  one  passes 
around  the  posterior  border  of  the  external  surface  of  the 
anterior  or  true  sinus.  The  apparent  second  sinus  is  undoubt- 
edly an  enlarged  cell  of  the  orbital  process  of  the  palate  bone. 
The  true  maxillary  sinus  is  extremely  small.  It  may  be  that 
on  account  of  this  the  cell  was  abnormally  enlarged  to  increase 

Fig.  48. 


Antero-posterior  division  through  the  center  of  the  orbit,  maxillary  sinus,  and 
teeth,  showing  an  enlarged  cell  of  the  orbital  process  of  the  palate  bone,  and  a  corre- 
spondingly small  maxillary  sinus. 

the  air  space  of  this  region,  or  that  the  palatal  process  has 
encroached  upon  the  space  usually  occupied  by  the  maxillary 
bone.  The  bony  septum  of  this  specimen  might  very  easily 
be  mistaken  for  a  division  parting  the  antrum  into  two;  but 
the  writer  would  not  thus  classify  it,  as  this  posterior  sinus 
opens  into  the  superior  meatus,  the  same  as  the  other  palatal 
cells  just  described. 

It  is  a  well-established  fact  that  the  maxillary  sinus  is  de- 
veloped by  an  invagination  of  the  mucous  membrane  of  the 
middle  meatus  into  the  body  of  the  maxilla.     If  there  should 


70 


INTERNAL   ANATOMY    OF    THE    FACE. 


be  two  of  these  invaginations,  it  could  then  be  easily  ac- 
cepted that  these  cells  are  a  divided  maxillary  sinus;  but  as 
the  outlet  of  the  posterior  one  is  into  the  superior  meatus, 
into  which  the  cells  of  the  orbital  process  of  the  palate  bone 
open,  it  seems  evident  that  this  is  an  enlarged  palatal  sinus 
or  cell,  and  not  a  divided  maxillary  sinus. 

Fig.  49  is  from  another  section  made  through  the  molar 
teeth  and  the  center  of  the  orbit.  Posterior  to  the  maxillary 
sinus,  we  find  another  sinus  of  a  different  character,  which  from 
superficial  observation  might  be  thought  to  be  related  to  it  or 

Fig.  49. 


Antero-posterior  division  through  the  center  of  the  orbit,  maxillary  sinus,  and 
molar  teeth,  showing  a  large  maxillary  sinus  and  a  large  sphenoidal  sinus. 

to  be  an  enlarged  cell  belonging  to  the  palate  bone.  A  probe 
passed  into  it  leads  into  the  supreme  or  fourth  meatus  of  the 
nose,  indicating  that  it  may  be  related  to  or  connected  with 
the  sphenoidal  sinus.  In  fact,  it  is  a  very  large  sphenoidal 
sinus  extending  out  laterally  in  a  line  almost  to  the  outer  part 
of  the  maxillary  bone. 

Fig.  50  gives  a  view  of  the  external  walls  of  the  nasal  fossae 
of  the  same  skull  as  Fig.  49.  The  sphenoidal  sinus  shown  in 
B  extends  laterally  until  it  forms  the  cavity  posterior  to  the 
maxillary  sinus  seen  in  Fig.  49.  It  will  be  observed  that  this 
large  sphenoidal  sinus  extends  well  forward  toward  the  frontal 
bone  and  backward  toward  the  basilar  process  of  the  occipital 
bone. 


THE   MAXILLARY   SINUS. 


71 


Fig.  51  is  an  outer  and  inner  view  of  a  section  showing  an 
extremely  large  sphenoidal  sinus.  In  A  the  cut  is  made 
through  the  premolar  teeth,  and  a  little  to  the  inner  side  of 


i^iG.  50. 


External   walls    of   right   and    left    nasal    chambers,   with   large    sphenoidal   sinuses,    B 
having  four  meati. 

Fig.  si. 


Two  views  of  an  antero-posterior  section.  A  shows  the  inner  wall  of  the  orbit, 
maxillary  sinus,  and  openings  leading  into  the  sphenoidal  sinus.  B  shows  the  external 
wall  of  the  nose  and  a  large  sphenoidal  sinus. 


the  middle  of  the  orbit,  exposing  the  inner  wall  of  the  maxil- 
lary sinus,  the  cell  of  the  palate  bone,  and  the  sphenoidal  sinus, 
over  which  is  seen  the  sella  turcica.     The  irregular  opening 


72  INTERNAL   ANATOMY    OF   THE    FACE. 

in  the  anterior  clinoid  process  in  A  leads  to  and  is  a  part  of 
the  sphenoidal  sinus.  In  B  the  external  wall  of  the  nose 
will  be  observed.  In  the  region  of  the  body  of  the  sphe- 
noid bone  is  a  very  large  sinus,  at  the  bottom  of  which  will 
be  noticed  a  space  under  the  sella  turcica  shown  in  A.  This 
is  the  largest  sphenoidal  sinus  which  has  come  under  the  ob- 
servation of  the  writer.  It  extends  forward  to  the  cribriform 
plate  of  the  ethmoid  bone;  backward  to  near  the  basilar 
process  of  the  occipital  bone;  laterally  on  a  line  with  the 
molar  teeth;  superiorly  into  the  anterior  clinoid  process,  with 
only  a  very  thin  plate  of  bone  between  it  and  the  floor  of  the 
anterior  fossa  of  the  brain-case.  In  such  cases  the  partition 
between  the  sphenoidal  sinus  and  the  maxillary  sinus  is  so 
thin  and  sieve-like  that  infected  fluids  will  readily  find  their 
way  from  the  former  to  the  latter. 

In  the  usual  physiological  description  of  the  sinus,  the  fluids 
are  spoken  of  as  passing  out  of  it.  It  is  a  question  if  this  be  the 
case  under  normal  conditions.  It  is  more  than  likely  that  the 
law  of  supply  and  demand  is  so  balanced  that  the  parts  of  the 
maxMary  sinus  are  kept  moist  only,  the  openings  being  so  ar- 
ranged at  the  top  as  to  prevent  undue  loss  of  the  fluids  while 
the  subject  is  lying  on  the  back  or  is  standing.  The  openings 
in  the  other  air  cells  or  sinuses  are  so  arranged  as  to  make 
almost  complete  drainage. 

Dental  Relationships.  Because  of  the  close  anatomical 
relation  of  the  maxillary  sinus  with  the  tooth-germs  and  the 
roots  of  the  permanent  teeth,  it  is  evident  that  the  sinus  must 
be  more  or  less  influenced  by  them.  As  the  teeth  develop  and 
descend  into  their  normal  places,  the  sinus  increases  in  size. 
If  a  tooth  situated  near  the  sinus  be  retarded  in  its  eruption, 
the  development  of  the  antrum  is  interfered  with  at  that 
particular  point.  If  the  root  of  a  tooth  be  left  in  the  jaw  in  old 
age,  resorption  immediately  over  that  root  will  not  progress 
as  in  the  parts  from  which  the  roots  have  been  removed.  (See 
Fig.  85.) 

It   has   been   shown   how   closely   the   apical   portions   of 


THE   MAXILLARY  SINUS.  "J}^ 

the  roots  of  the  teeth  are  often  associated  with  the  sinus. 
{See  Figs.  25,  26,  and  41.)  This  close  proximity  gives  the 
impression  that  the  maxillary  sinus  is  oftener  infected  from 
diseased  teeth  than  from  any  other  source,  some  authori- 
ties claiming  that  three-fifths  of  the  diseases  of  the  antrum  are 
brought  about  in  that  way.  The  writer  thinks  this  a  mis- 
take.. Though  recognizing  that  diseases  of  the  antrum  do 
arise  from  the  teeth,  he  believes  that,  aside  from  constitutional 
diseases  and  malformations,  it  is  more  often  through  the  com- 
mon communication  between  the  nasal  chamber,  the  frontal 
sinuses,  the  ethmoidal  cells,  and  the  maxillary  sinus,  that  in- 
fection is  conveyed  to  the  antrum  from  diseased  cells  and 
sinuses  above  it.  He  recognizes,  at  the  same  time,  that 
the  posterior  ethmoidal  and  sphenoidal  cells  and  the  cells  of 
the  orbital  process  of  the  palate  bone  can  also  infect  the  an- 
trum by  resorption  of  the  partition  between  these  cavities.  It 
is  the  writer's  observation  that  there  are  more  cases  in  which 
teeth  are  lost  through  diseases  of  the  antrum  than  cases  in 
which  the  teeth  are  primarily  diseased,  causing  infection  of 
the  antrum  and  associated  cells.  In  Fig.  26  it  will  be  observed 
that  the  anterior  buccal  and  palatal  roots  of  the  first  molar 
tooth  pass  up  into  the  walls  of  the  antrum.  This  is  the  class 
of  cases  where  diseased  teeth  may  cause  infection  of  the  max- 
illary sinus.  If  the  pulp  of  a  tooth  so  related  to  the  antrum 
should  become  devitalized  and  infected,  the  parts  around  the 
apical  foramen  might  also  become  infected  and  abscesses  oc- 
cur. From  the  close  proximity  of  the  points  of  the  roots  to 
the  sinus,  it  might  be  supposed  that  these  abscesses  would 
break  into  the  antrum,  as  they  occasionally  do.  Other  ex- 
amples of  infection  of  the  antrum  through  diseased  teeth  in 
no  way  mihtate  against  the  idea  that  the  teeth  are  not  first  in 
importance  as  factors  in  causing  disease  of  the  antrum. 

It  is,  however,  clear  that  pus  or  infected  matter  will  pass 
in  the  direction  of  the  least  resistance.  When  the  investing 
tissues  of  a  tooth  become  so  infected,  the  osteogenetic  layer 
of  the  muco-periosteum  stimulates  renewed  activity,  with  the 


74  INTERNAL    ANATOMY    OF    THE    FACE. 

result  that  a  new  layer  of  bone  is  produced  by  it  which  covers 
these  parts  and  protects  this  cavity  so  that  abscesses,  with  but 
few  exceptions,  point  and  break  into  the  mouth. 

Careless  operation  by  the  dentist  sometimes  causes  infec- 
tion of  the  sinus,  as  drilling  through  the  tooth  and  the  floor  of 
the  sinus,  or  forcing  the  root  of  a  tooth  into  the  sinus,  through 
fracture  of  the  wall  in  an  unskillful  effort  to  extract,  or  care- 
lessness in  driving  artificial  crowns  or  bridges  upon  the  teeth 
or  roots. 

Fig.  52  gives  a  view  of  an  undeveloped  and  unerupted 
third  molar  which  was  causing  irritation  in  the  floor  of  the 
sinus. 

Fig.  58  is  from  the  opposite  side  of  the  same  skull,  show- 
ing a  similar  condition  and  with  an  abscess  which  has  burrowed 
under  the  mucous  membrane  near  the  roots  of  the  first  molar 
tooth. 

Fig.  54  is  a  view  of  an  antero-posterior  section  of  the  upper 
jaw  with  the  first  molar  decayed  and  the  pulp-chamber  of  the 
tooth  open.  The  root-canal  has  been  infected  and  the  infec- 
tion has  been  carried  into  the  sinus.  In  this  case  there  is 
evidence  of  a  constructive  periostitis  upon  the  floor  of  the 
antrum,  which  has  caused  a  thickening  of  bone  over  the  apex 
of  the  root.  At  a  later  period  suppurative  inflammation  has 
occurred  and  perforated  the  floor  of  the  antrum. 

Fig.  55  is  a  view  of  the  floor  of  the  antrum  and  the  nasal 
chamber.  In  the  middle  of  the  antrum  there  is  a  conical 
elevation  with  an  opening  in  the  center  exposing  the  apex  of 
a  tooth.  In  this  case  new  bone  has  been  formed  over  the 
diseased  root,  but  at  some  subsequent  time  the  bone  has  been 
broken  down  and  the  antrum  has  become  infected. 

Fig.  56  is  a  vertical  transverse  section  of  the  sinuses  and 
nasal  chamber.  In  the  floor  of  the  right  antrum  the  conical 
portion  of  the  bone,  covering  the  infected  tooth,  has  been 
cut  through  its  center,  exposing  the  end  of  the  root  in  the 
infected  region,  the  condition  being  somewhat  similar  to  those 
shown  in  Figs.  54  and  55. 


Till':    M.\XIIJ.AI<^•    SIM/S. 

Fig.  ^2. 


B 


75 


Antero-posterior  division  through  the  orbit,  frontal  and  maxillary  sinuses,  and  molar 
teeth,  showing  an  undeveloped  molar  which  was  causing  irritation  in  the  floor  of  the 
sinus. 


76 


INTERNAL   ANATOMY   OF   THE    FACE. 


Fig.  57  is  made  from  the  left  maxilla  of  the  same  skull  from 
which  Fig.  54  was  taken.    The  pulp  of  the  first  molar  was  de- 

FiG.  S3. 


B 

Antero-posterior  division  through  the  orbit,  frontal  sinus,  maxillary  sinus,  and  molar 
teeth,  showing  a  similar  condition  as  in  Fig.  52.  An  abscess  has  burrowed  under  the 
mucous  membrane  near  the  roots  of  the  first  molar  tooth. 

vitalized.     In  B  quite  an  exostosis  over  the  position  of  the 
infected  root  is  seen.      An  examination  of  the  hard  palate 


THE   MAXILLARY   SINUS. 


17 


shows  that  the  discharge  of  the  abscess  was  made  into  the 
mouth,  which  the  writer  beheves  is  the  usual  outlet  for  apical 


Fig.  54. 


Sound  passing  through 

Infraorbital  Canal 

and  Foramen. 


Infraorbital  Sinus,  -r 


Infraorbital  Foramen. 


Maxillary    Sinus. 


Opening  caused  by 
Apical  Abscess. 


-Infraorbital   Sinus. 


Opening  into  Malar  Bone. 


Antero-posterior  division  of  the  maxilla,  showing  opening  of  a  dental  abscess  withirt 
the  antrum  and  an  infraorbital  sinus. 

abscesses  in  the  upper  jaw, — of  course  recognizing  that  they 
occasionally  open  into  the  antrum. 


/O  INTERNAL    ANATOMY    OF    THE    FACE. 

It  has  been  shown  by  these  examples  how  numerous  are  the 
variations  of  the  maxillary  sinus  in  shape,  size,  and  position, 
and  in  its  relation  to  the  mouth  and  teeth,  the  nasal  chamber, 
the  frontal  sinus,  the  ethmoidal  cells,  the  cell  of  the  orbital 
process  of  the  palate  bone,  and  the  sphenoidal  sinus.  The 
variations  are  most  important  to  the  dentist  and  rhinologist. 
In  the  field  of  stomatology,  so  many  compHcations  often 
arise  in  the  extraction  and  treatment  of  teeth  that  a  thor- 
oughly scientific  knowledge  of  the  results  of  all  recent  re- 
search in  this  region  is  absolutely  necessary. 


Fig.  55. 

Floor  of  the  Nasal  Fossa. 


Apical   Foramen  of  Tooth. 
Floor  of  INIaxillary  Sinus. 


Horizontal    section    above    the    right    floor    of    the    nasal    fossa    and    maxillary    sinus, 
showing  the  opening  of  a  dental  abscess  in  the  floor  of  the  antrum. 


Surgical  Relations.  In  the  extraction  of  the  upper  molar 
teeth  great  care  should  be  exercised,  because,  as  has  been 
shown,  where  the  antrum  is  large,  extending  downward  and 
inward  between  the  roots  of  the  teeth,  as  seen  in  Figs.  25,  26. 
and  94,  if  undue  force  should  be  exerted,  not  only  the  tooth 
grasped  by  the  forceps,  but  also  a  great  portion  of  the  floor 
of  the  antrum  with  other  teeth  attached  is  liable  to  be  carried 
away.  Examples  of  the  results  of  such  accidents  are  shown 
in  Fig.  58.     A  and  B  are  from  specimens  broken  away  with 


THE   MAXILLARY   SINUS. 


79 


the  ordinary  forceps,  and  C  is  from  a  specimen  of  the  work 
of  the  old-fashioned  turnkey.  When  using  much  force  in 
placing  artificial  bridges  or  crowns  upon  the  teeth  immedi- 
ately beneath  the  antrum,   there  is  danger  of  breaking  the 


Fic 


Portion  of  Eje.^ 


ilarged  Middle  ) 
urbinate   Bone.  / 


Orbit. 


,_  Middle 
Turbinate. 

Middle  Meatus. 
Maxillary  Sinus. 


Anterior  view  of  a  vertical  transverse  section  in  the  region  of  the  crista  galli,  middle 
of  orbit,  and  molar  teeth,  showing  effect  of  dental  abscess  in  floor  of  maxillary  sinus. 

floor  in  subjects  where  the  walls  are  thin.  When  the  pulps 
of  the  teeth  have  become  diseased  and  infected,  the  in- 
fection may  pass  out  of  the  apical  foramen  into  the  tissues 
immediately  surrounding  the  root,  and  thence  into  the  an- 
trum,   as    has    before    been    mentioned.     In    cleansing    the 


8o 


INTERNAL   ANATOMY    OF   THE    FACE. 


root-canal  there  is  some  danger  of  passing  the  instrument 
through  the  apical  foramen  directly  into  the  sinus.  Soreness 
of  the  teeth  caused  by  inflammation  of  the  peridental  mem- 
brane with  abscesses  threatening  to  open  into  the  mouth,, 
sometimes  disappears  suddenly,  although  no  fistulous  opening 
into  the  mouth  has  formed.  When  this  occurs  the  abscess 
has  frequently  found  an  opening  into  the  sinus.  Diseases  of 
the  maxillary  sinus  are  liable  to  produce  disturbances  in  the 

Fig.  57- 


}  FM  S 


FMS 


Horizontal  sections  through  the  maxillary  sinus.  FMS,  floor  of  the  maxillary 
sinus.  In  B  there  is  an  exostosis  over  the  position  of  an  infected  root  of  the  first  molar 
tooth.  In  A  the  cap  of  bone  covering  the  root  has  been  removed,  exposing  the  end  of 
the  root  and  a  fistula  extending  downward,  opening  into  the  roof  of  the  mouth. 


teeth,  as  their  blood  supply  passes  along  the  floor  of  the 
antrum  and  through  the  wall.  Branches  of  the  fifth  nerve 
accompany  the  vessels,  and  these  also  are  Hable  to  become 
deranged  in  their  true  function. 

The  maxillary  sinus  is  on  a  lower  plane  than  any  of  the 
other  sinuses  and  cells  associated  with  the  nasal  chamber, 
and  has  its  outlet  in  the  upper  anterior  portion;  when  the 
hiatus  semilunaris  is  blocked  below  or  posterior  to  the  open- 
ing of  the  sinus,  it  becomes  engorged  with  the  fluids  which 
have  no  other  normal  exit,  thus  producing  pressure  upon  its 


THE   MAXILLARY   SINUS. 


8i 


walls  and  upon  the  nerves  and  vessels  passing  through  it.  It 
is  in  such  cases  that  additional  openings  are  found  leading 
from  the  maxillary  sinus.     (See  Figs.  95,  96,  and  97.) 

Fig.  58. 


B 


Three  pieces  of  bone  with  molar  teeth  that  have  been  accidentally  broken  away 
with  part  of  the  floor  of  the  maxillary  sinus  in  extraction ;  A  and  B  with  ordinary  for- 
ceps, C  with  an  old-fashioned  turnkey. 


82  INTERNAL   ANATOMY    OF    THE    FACE. 


THE  FRONTAL  SINUS. 


The  frontal  sinuses  are  two  irregular  shaped  chambers 
situated  in  the  lower  part  of  the  facial  portion  of  the  frontal 
bone  and  in  the  process  forming  the  roofs  of  the  orbits,  with 
a  thin  lamina  of  bone  between  them.  They  vary  considerably 
in  size,  shape,  and  position. 

Development.  They  appear  about  the  second  year  after 
birth  and  are  formed  by  an  invagination  from  the  upper  an- 
terior portion  of  the  hiatus  semilunaris  and  by  a  dissolution 
of  the  tissue  between  the  outer  and  inner  plates  of  the  frontal 
bone,  the  excavations  for  the  formation  of  these  sinuses  as 
well  as  for  the  various  other  cells  and  sinuses  being  supposedly 
carried  on  through  the  agency  of  the  osteoclasts.  The  sinuses 
continue  to  increase  in  size  until  advanced  age.  They  some- 
times extend  over  the  greater  part  of  the  orbit  and  even  as 
high  as  the  frontal  eminences.  They  are  lined  with  mucous 
membrane  and  communicate  with  the  nasal  chambers  through 
the  infundibulum  and  the  hiatus  semilunaris. 

Fig.  59  shows  a  large  left  frontal  sinus,  which  passes  over  to 
the  right  of  the  median  line,  leaving  but  little  room  for  the 
right  sinus  in  its  normal  position,  as  is  seen  in  B.  Often,  in 
such  cases,  the  opposite  side  will  extend  its  air  space  in  some 
other  direction  to  make  up  for  the  loss  caused  by  the  invasion. 

Fig.  60  is  made  from  B  of  Fig.  59,  cut  through  the  center 
of  the  orbit,  showing  that  the  frontal  sinus  has  extended  back 
over  the  orbit  to  the  region  of  the  optic  foramen.  It  has  also 
extended  outward  under  the  external  angular  process  of  the 
frontal  bone. 

Fie.  61  is  made  from  a  skull  where  the  frontal  sinus  has 


riil'.    I'ROMTAL    SIMS. 

Fig.  59. 


83 


External   walls   of  the   nasal   chamber   showing  the   left   frontal   sinus    extended   over 
to  the  right  of  the  median  line. 


Fig.  60. 


Two  antero-posterior  sections  (made  from  B  of  Fig.  59)  through  the  frontal  sinus, 
center  of  orbit,  maxillary  sinus,  and  cell  of  the  orbital  process  of  the  palate  bone, 
showing  the  frontal  sinus  extending  backward  over  the  orbit  to  the  region  of  the 
optic  foramen.     It  also  extends  under  the  external  angular  process  of  the  frontal  bone. 


84 


INTERNAL    ANATOMY    OF    THE    FACE. 


Fig.  6i. 


Two   vertical   transverse   sections   through   the   frontal   sinuses   and   nasal    chambers, 
showing  the  frontal  sinus  extending  below  the  level  of  the  middle  of  the  orbit. 


Fig.  62. 


Large   frontal   sinuses   extending    from   one   external  .  angular   process   of  the   frontal 
bone  to  the  other. 


THE    FRONTAL    SINUS.  85 

extended  upward  under  the  region  of  the  frontal  eminence 
and  downward  to  the  middle  of  the  orbit  or  almost  on  a  level 
with  the  upper  portion  of  the  maxillary  sinus. 

Fig.  62  is  an  illustration  of  large  frontal  sinuses,  extend- 
ing from  one  external  angular  process  of  the  frontal  bone 
to  the  other,  with  but  a  thin  complete  septum  between.  This 
septum  is  not  in  the  center,  but  is  carried  to  the  left  side.  The 
sinuses  pass  backward  over  the  greater  portion  of  the  orbits, 
and  upward  toward  the  frontal  eminence.  There  is  quite  a 
depression  over  the  frontal  crest,  which  is  very  large  in  this 
specimen.  There  are  also  several  partial  septa  running  in 
various  directions  in  the  two  sinuses. 


INTERNAL    ANATOMY    OF    THE    FACE. 


THE  ETHMOIDAL  AND  OTHER  CELLS  WHICH 

HAVE  THEIR  FINAL  OUTLET  IN  THE 

NASAL  FOSSAE. 


The  ethmoidal  cells  are   situated    principally    between    the 
two  orbits.     Fig.  63  is  an  upper  view  of  a  horizontal  section 


Fig.  63. 


^asai  ch 


^mh 


Anterior 
Ethmoidal   Cells. 


^7 

Floor   of   Orbit.  -^1_  >. 


Middle 
Ethmoidal   Cells. 


Z-'    ' 


Posterior  Ethmoidal  Cells.  / 

Sphenoidal    Sinuses. 

Upper    surface    of   a    horizontal    section    cut    through    the    orbits    and    upper    part    of 
nasal  fossa. 

cut  through  the  center  of  the  orbits  and  the  upper  part  of 
the  nasal  chambers,  showing  clearly  the  position  of  many  of 
the  cells,  as  does  also  Fig.  39.  Many  of  these  ethmoidal  cells 
are  formed  by  the  union  of  the  orbital  plates  of  the  frontal 
bone  and  the  ethmoid  bone  and  between  the  ethmoid  bone 


THE    ETHMOIDAL    AND    OTHER    CELLS.  8/ 

and  the  maxilla;  others  are  within  the  ethmoid  alone.  They 
are  divided  into  three  groups,  anterior,  middle,  and  posterior. 

The  anterior  ethmoidal  cells  are  the  smallest  of  the  three 
divisions.  They  open  by  several  small  orifices  into  the  ante- 
rior portion  of  the  hiatus  semilunaris.  Occasionally  a  chain 
of  cells  is  found  opening  one  into  another  and  finally  into  the 
hiatus. 

The  middle  ethmoidal  cells  vary  more  in  size  than  either 
the  anterior  or  the  posterior.  The  inner  covering  or  wall  of 
the  cells  is  spheroidal  in  form  and  is  known  as  the  bulla  eth- 
moidalis.  It  is  situated  in  the  upper  portion  of  the  lateral  wall 
of  the  hiatus  semilunaris,  and  extends  downward  and  inward 
toward  the  unciform  process.  The  openings  of  the  cells  are 
in  the  outer  portion  of  the  bulla  ethmoidalis  and  they  dis- 
charge into  the  hiatus  semilunaris. 

The  posterior  ethmoidal  cells  are  usually  two  or  three  in 
number.  They  are  found  on  about  the  same  plane  as  the 
anterior  and  middle  ethmoidal  cells,  are  irregular  in  shape, 
and  usually  have  their  general  outlet  into  the  superior  meatus. 


The  cells  of  the  orbital  process  of  the  palate  bone  are  two 
in  number,  one  on  each  side.  Each  cell  is  small  and  situated 
below  the  posterior  part  of  the  floor  of  the  orbit.  It  is,  like 
many  other  air  cells,  irregular  in  shape  and  size.  It  opens 
into  the  third  or  superior  meatus.  It  occasionally  extends 
backward  near  to  the  sphenoidal  sinus  or  outward  around  the 
posterior  wall  of  the  maxillary  sinus,  from  which  it  is  sepa- 
rated by  a  thin  plate  of  bone.     (See  Fig.  48.) 


The  sphenoidal  sinuses  are  two,  one  on  each  side,  irregular 
in  shape  and  size,  situated  in  the  body  of  the  sphenoid  bone. 
(See  Figs.  50  and  51.)  The  septum  between  them  is  generally 
deflected  to  one  side  or  the  other.  (See  Figs.  63  and  81.)  In- 
complete septa  may  also  be  found  at  the  posterior  portion  of 


88  INTERNAL   ANATOMY    OF   THE    FACE. 

these  cavities,  which  divide  them  into  several  incomplete  com- 
partments, (See  Fig.  8i.)  Sometimes  these  sinuses  may  ex- 
tend backward  to  the  basilar  process  of  the  occipital  bone, 
or  forward  to  the  cribriform  plate  of  the  ethmoid  bone,  or 
laterally  into  the  base  of  the  great  wings  of  the  sphenoidal 
bone,  or  into  the  clinoid  process.  (See  Fig.  51.)  They  are 
lined  with  mucous  membrane,  which  is  continuous  with  that 
lining  the  upper  and  posterior  portion  of  the  nasal  cavities. 
They  empty  into  the  highest  meatus. 


Cell  of  the  crista  galli.  Sometimes  a  cell  is  found  within 
the  crista  galh.  (See  Figs.  74,  82,  90,  91,  92,  and  93.)  In 
such  a  case  the  opening  is  in  front  and  communicates  with  one 
of  the  frontal  sinuses.  It  might  be  termed  an  extension  of  the 
frontal  sinus  into  the  crista  galli. 


ANATOMICAL    N'AKIATIONS. 


89 


VARIATIONS    IN   THE   ANATOMICAL  STRUC= 
TURES  OF  THE  FACE. 


It  has  been  the  endeavor  thus  far  to  describe  the  jaws  and 
their  associated  parts  and  to  speak  only  of  what  might  be 
termed  typical  anatomy.  At  the  same  time,  great  variations 
have  been  referred  to.  These  variations  are  so  common  that 
it  is  difficult  at  times  to  state  which  is  normal  and  which  is 
abnormal  anatomy.     Some  of  the  most  important  and  com- 

FlG.  64. 


Front  view 
left  side. 


of  asymmetrical  skull,  showing  the  right  side  of  the  face  fuller  than  the 


mon  variations  found  in  the  writer's  dissections  are  described 
in  pages  following. 

Fig.  64  is  a  front  view  of  a  skull  which  has  an  unsymmetrical 
arch  of  the  mouth.  The  greater  portion  of  the  teeth  have 
been  lost  in  early  life.  The  canine  fossa  of  the  right  side  is 
lacking,  the  face  being  bulged  out  at  that  point.     The  teeth 


90 


INTERNAL   ANATOMY    OF    THE    FACE. 


have  not  been  in  normal  position.  The  septum  is  deflected 
toward  the  right  side.  In  a  skiih  of  this  character  the  internal 
structures  will  usually  be  decidedly  unsymmetrical.  One 
might  suppose  that  a  large  antrum  would  be  found  under  the 
fullness  of  the  canine  fossa,  but  in  this  particular  case  it  is 
not  so  found. 

Fig.    65    represents    a   vertical    transverse    section    of   the 

Fig.  65. 


Vertical  transverse  division  of  Fig.  64,  showing  a  larger  maxillary  sinus  on  the  left 
side  than  on  the  right. 

skull  shown  in  Fig.  64.  It  will  be  seen  that  the  right  antrum 
is  smaller  than  the  left,  the  fullness  of  the  region  in  the  infra- 
orbital foramen  and  the  canine  fossa  being  due  to  the  thick- 
ness of  the  bone.  The  frontal  sinus  of  this  specimen  is  large 
and  extends  downward  between  the  orbits  lower  than  usual. 

Fig.  66  exhibits  a  condition  occasionally  met  with,  the  floor 
of  the  antrum  dipping  downward  and  passing  partly  under  the 
floor  of  the  nose.     The  same  condition  will  be  found  in  Fig. 


AXATOMICAL   X'ARIATIOXS. 


91 


94,  and  in  B,  Fig.  83.  Resorption  has  taken  place  between  the 
plates  forming  the  floor  of  the  nose  and  the  roof  of  the  mouth. 
Sinuses  like  these  could  be  drained  directly  l:)y  an  opening 


Fig.  66. 


Anterior  view  of  a  vertical  transverse  section  of  skull  through  center  of  orbits,  nasal 
chamber,  and  maxillary  sinus,  the  lower  inner  corners  of  the  maxillary  sinuses  passing 
partly  under  the  nasal  fossse. 

Fig.  67. 


^ 


Posterior  view  of  a  vertical  transverse  section  of  skull  in  region  of  second  premolar, 
showing  lack  of  symmetry  in  nasal  fossae  and  maxillary  sinuses,  with  the  septum  and 
"spur"  passing  over  to  the  inferior  turbinate. 

through  the  palatal  surface  of  the  mouth.     In  skulls  of  this 
character  the  vault  of  the  mouth  is  high. 

Fig.  67  exhibits  an  entire  lack  of  symmetry  between  the 
nasal  fossje  and  the  sinuses  of  the  right  and  left  sides,  the 


92 


INTERNAL   ANATOMY    OF   THE    FACE. 


inferior  meatus  of  one  side  being  closed  anteriorly  by  the 
deflected  nasal  septum  and  the  ''spur"  upon  it.  In  such  cases 
as  this,  inspissated  mucus  often  collects  and  the  outlet  of  the 
lachrymal  duct  may  be  interfered  with. 

Figs.  68,  69,  and  70  are  from  the  same  subject  as  Fig.  67. 
An    instrument    passed    through    the    axis    of    the    alveolar 

Fig.  68. 


Anterior  view  of  a  vertical  transverse  section  of  the  sknll  shown  in  Fig.  67,  showing 
an  asymmetrical  condition  of  the  two  sides. 

Fig.  69. 


Posterior  view  of  section  shown  in  Fig.  68. 


process  shown  in  the  right  side  of  Fig.  69  or  the  left  side  of 
Fig.  68  or  Fig.  70  would  perforate  the  nasal  fossa,  instead  of 
the  floor  of  the  antrum. 

Fig.  71,  which  is  taken  from  a  different  skull,  shows  an 


ANATOMICAL   VAKIATIOXS. 


93 


almost  straight  septum,  with  bilateral  symmetry  as  to  the 
nasal  chamber;  the  maxillary  sinuses  vary,  however,  through- 
out the  depth  of  the  skull.  On  the  right  side  the  antrum 
would  not  be  reached  by  drilling  through  the  alveolar  process, 


Fig.  70 


Anterior  view  of  vertical  transverse  section  cut  from  the  posterior  part  of  the  nasal 
fossse  and   maxillary  sinus.     It  is  from  the   same  skull  as   Figs.   67,   68,   and  69. 


Fig.  71. 


Anterior  view  of  a  vertical  transverse  section  showing  lack  of  uniformity  in  the  two 
maxillary  sinuses. 


while  on  the  left  side  the  sinus  is  just  above  the  process,  and 
the  floor  is  below  the  level  of  the  floor  of  the  nose. 

Fig.  ']2  is  from  a  vertical  transverse  section  in  the  region  of 
the  first  premolar.  The  septum  is  almost  straight,  but  there  is 
a  great  variation  in  the  maxillary  sinuses.     The  outer  wall  of 


94 


INTERNAL    ANATOMY    OF   THE    FACE. 


the  nasal  chamber  of  the  right  side  is  also  the  outer  plate  of  the 
maxilla,  the  floor  of  the  antrum  being  on  a  much  higher 
plane.  In  the  floor  of  the  left  nasal  chamber  is  an  elevation 
which  covers  a  tooth  root,  more  than  likely  that  of  a  super- 
numerary tooth. 

In  Figs.  68  and  72  the  nasal  walls  of  the  right  inferior 
meatus  pass  outward  under  the  maxillary  sinus  to  the  facial 
portion  of  the  maxillary  bone.  In  Figs.  75  and  A,  Fig.  83,  the 
same  condition  will  be  observed  on  both  sides  of  the  illustra- 


FlG.    ']2. 


Anterior    view    of    a    vertical    transverse    section,    near    the    first    premolar,    showing 
variations  in  the  maxillary  sinuses  and  the  nasal  fossa;. 


tion.  In  the  event  of  attempting  to  drill  into  the  maxillary 
sinus  from  the  canine  fossa  in  such  cases  as  are  represented  in 
these  figures,  as  is  sometimes  advised,  the  opening  would  be 
made  into  the  nasal  chamber  instead  of  into  the  sinus. 

Fig.  73  is  a  view  of  a  vertical  transverse  section  from  a  skull 
in  the  region  of  the  second  molar.  The  septum  is  straight, 
the  nasal  chamber  and  the  appendages  and  the  maxillary 
sinuses  are  small,  and  do  not  extend  downward  in  the  direction 
of  the  teeth  and  the  alveolar  process. 

Fig.  74  shows  two  sections  from  the  same  skull  as  Fig.  73, 
cut  more  anteriorly,  in  the  region  of  the  premolars.     The  parts 


ANATOMKAr,   VARIATIONS. 
Fig.  72,. 


95 


Posterior  view  of  a  vertical  section  made  in  the  region  of  the  molar  teeth,  showing 
small  antra  and   large  nasal  fossje. 

Fig.  74. 


Two  vertical  transverse  sections.  The  surfaces  shown  are  divided  from  each  other. 
\'ariations  are  shown  in  the  antra  and  nasal  fossre.  A  cell  is  also  shown  within  the  crista 
galli,  which  opens  into  the  frontal  sinus. 


96 


INTERNAL   ANATOMY    OF   THE    FACE. 


are  almost  symmetrical.  The  crista  galli  has  been  cut  trans- 
versely, showing  within  its  walls  a  cell  of  considerable  size, 
opening  into  the  frontal  sinus. 

Fig.  75  is  made  from  the  skull  of  an  old  subject,  in  which 
the  bones  have  become  much  resorbed.  It  is  comparatively 
symmetrical,  with  the  floor  of  the  sinus  much  higher  than 
usual,  and  the  nasal  fossa  extending  outward  to  the  external 
portion  of  the  maxillary  bone. 

Fig.  75. 


Anterior    view    of    a    vertical    transverse    section    from    the    skull    of    an    old    person, 
showing  large  nasal  fossae  with  small  antra. 


Occasionally  in  surgical  practice  abscesses  are  found  open- 
ing on  the  face  in  the  region  of  the  mal^r  bone.  These  are 
usually  looked  upon  as  of  superficial  origin,  but  sometimes 
when  carefully  examined  they  are  found  to  be  associated  with 
the  maxillary  sinus.  Fig.  76  will  partly  explain  why,  in  some 
cases,  abscesses  of  the  maxillary  sinus  open  at  this  point.  The 
section  is  made  at  the  region  of  the  maxillo-malar  articula- 
tion. The  maxillary  sinus  passes  far  into  the  malar  bone,  ex- 
tending backward  into  the  zygomatic  process. 

Fig.  yj  is  from  a  skull  in  which  the  nasal  chamber  extends 
outward  over  the  alveolar  process  until  it  reaches  the  outer 
wall  of  the  maxillary  bone.  The  points  of  the  palatal  roots  of 
the  first  and  second  molars  appear  in  the  floor  of  the  nasal 


ANATOMICAL  \AKiATIOXS. 


97 


chamber.     The  floor  of  the  maxillary  sinus  is  well  up  on  the 
side  of  the  bone. 

Fig-.  78  is  a  picture  from  the  external  or  facial  surface  of 

Fig.  76. 


Section  through  the  maxillo-malar  articulation,   showing   {hat  occasionally  the  maxil- 
lary sinus  passes   into  the  malar  bone. 

Fig.  "jt. 


Interior  view  of  the  external  wall  of  the  nasal  fossa,  showing  portions  of  the  pala- 
tal roots  of  the  first  and  second  molar  teeth  in  the  floor  of  the  nose. 

Fig.  78. 


External  view   of  facial  surface  of  Fig.   "j-j,  showing  the  absorption   of  the  outer  part 
of  the  alveolar  process,  leaving  a  line  of  bone  near  the  free  margin  of  the  process. 


98  INTERNAL    ANATOMY    OF    THE    FACE. 

Fig.  75,  which  iUustrates  that  the  resorption  of  the  alveolar 
process  from  over  the  buccal  roots  of  the  teeth  may  progress 
while  that  portion  of  the  bone  along  the  free  margin  of  the 
process  is  left  intact. 

Fig.  79  shows  a  vertical  transverse  section  of  the  upper  jaw. 
In  B  the  roof  of  the  maxillary  sinus  is  almost  horizontal, 
which  is  a  very  unusual  condition.  The  illustrations  show 
what  is  apparently  a  division  of  the  sinus  into  two,  the  smaller 
or  outer  division  forming  an  infraorbital  sinus.  This  condi- 
tion is  caused  by  a  bony  septum  passing  down  from  the  center 
of  the  floor  of  the  orbit,  cutting  off  a  portion  of  the  sinus, 
and  forming  an  extra  chamber,  which  of  course  is  continuous 
with  the  true  sinus.  In  the  center  of  the  septum-like  wall  is 
a  tube  or  canal  conveying  the  infraorbital  nerves  and  vessels. 
Above  this  and  at  the  junction  of  the  septum  with  the  floor 
of  the  orbit  is  an  adjunct  infraorbital  canal  and  nerve.  At 
the  upper  inner  corner  of  B  is  the  normal  opening  of  the  max- 
illary sinus,  the  ostium  maxillare,  communicating  with  the 
hiatus  semilunaris.  This  section  beautifully  illustrates  how 
the  hiatus  semilunaris  is  bounded  on  the  inner  side  by  the 
uncifonn  process,  on  the  outer  side  by  the  wall  of  the  sinus, 
and  above  by  the  bulla  ethmoidalis,  containing  the  middle 
ethmoidal  cells. 

Fig.  80  illustrates  a  vertical  transverse  section  of  the  face. 
It  gives  a  good  sectional  view  of  the  posterior  ethmoidal  cells. 
The  white  line  is  on  a  level  with  the  floor  of  the  orbit  in  the 
anterior  portion  of  the  section.  It  will  be  noticed,  as  is  often 
the  case,  that  the  roof  of  the  maxillary  sinus  runs  up  as  it  passes 
backward  until  it  is  far  above  the  level  of  the  floor  of  the  orbit 
at  its  anterior  margin. 

Fig.  81  shows  two  sections  made  by  a  horizontal  transverse 
section  a  little  below  the  roof  of  the  sinus.  In  this  case  the 
commencement  of  the  ostium  maxillare  is  within  the  roof. 
It  passes  backward  and  inward  to  the  hiatus  semflunaris. 
A  probe  placed  in  the  left  ostium  maxillare  indicates  its  posi- 
tion.    Immediately  to  the  left  of  the  probe  is  a  section  of  the 


ANATOMICAL   VARIATKUXS. 

Fig.  79. 


99 


Infraorbital   Nerve. -^^:^^     fHSHI^?'" 


Muscles  of  Face. J  -i^^:  ■^■■y 


Middle   Ethmoidal   Cells. 


Middle    Turbinate. 
Unciform   Process. 


^—Inferior  Turbinate. 
Inferior  Meatus. 


Middle 
Ethmoidal   Cells 


Hiatus    Semilunaris.—^ 
Unciform  Process. 


Maxillary  Sinus 
Inferior    Turbinate. 


Vertical  transverse  division  of  the  upper  jaw. 


lOO  INTERNAL   ANATOMY   OF   THE    FACE, 

lachrymal  duct.  On  the  opposite  side,  the  lower  wall  of  the 
right  ostium  has  been  reinoved. 

That  the  great  variations  found  in  the  nasal  chamber  and 
maxillary  sinuses  may  be  fully  appreciated,  skulls  of  widely 
different  types  have  been  selected  and  photographed  together. 

Fig.  82  gives  a  posterior  view  of  two  sections  made  from 
different  skulls.  They  show  great  variations  in  the  depth  of 
the  face,  and  the  size,  shape,  and  position  of  the  maxillary 
sinus.     In  A  the  sinuses  are  much  smaller  than  in  the  shorter- 

FiG.  80. 


Posterior  view  of  vertical  section  through  the  orbits,  maxillary  sinuses,  posterior  eth- 
moidal cells,  and  the  third  molar  teeth. 

faced  picture  B.  In  A  the  septum  has  a  spur  extending  out- 
ward until  it  comes  in  contact  with  the  inferior  turbinate,  and 
the  frontal  sinuses  pass  well  down  below  the  level  of  the  center 
of  the  orbits.  In  both  illustrations  there  are  distinct  cells  in 
the  crista  galli,  which  open  anteriorly  into  the  frontal  sinuses. 
Fig.  83  was  made  in  the  same  manner  as  Fig.  82,  and  shows 
two  sections  cut  in  about  the  same  position  from  two  different 
skulls.  There  is  again  a  great  difference  in  the  depth  of  the 
faces.  The  maxillar^^sinuses  in  A  are  small  and  placed  high 
up,  allowing  the  lower  portion  of  the  nasal  chamber  to  extend 
outward  over  the  alveolar  process.  In  B  the  maxillary  sinuses 
are  large,  their  floors  extending  down  below  the  floor  of  the 


ANATOMICAL  VARIATIONS. 

Fig.  8i. 


roi 


Ostium  ^laxillare 
Opening   in    Roof. 

Roof  of  Maxillary 
Sinus. 

—Middle    Turbinate. 
— Hiatus   Semilunaris. 

Middle  Meatus. 


Superior  Meatus. 
Sphenoidal  Sinus. 


Mid.  Meatus. 
Maxil.  Sinus. 

Inf.  Turbinate. 
Malar  Bone. 

Lachrymal 
Duct. 


yasal  Septum. 


Two  illustrations.     A  shows  the  roof  of  the  maxillary  sinus  and  upper  portion  of  the 
nasal  fossas;   B   shows  the   maxillary  sinus  and  nasal   fossje. 


102  INTERNAL    ANATOMY    OF    THE    FACE. 

nasal  chamber,  and  passing  inward  over  the  roof  of  the  mouth, 
so  that  only  a  small  space  is  left  between  the  sinuses.  The 
enlarged  sinuses  allow  but  little  room  for  the  nasal  chambers. 

Fig.  84,  also  made  from  two  different  skulls,  shows  varia- 
tions in  the  depth  of  the  nasal  chambers.  A  gives  a  good 
illustration  of  the  fourth  meatus  and  a  partial  fifth. 

(Great  variations  in  the  size  and  shape  of  the  under  surface 
of  two  jaws  may  be  seen  in  Fig.  129.) 

Figs.  82,  83,  and  84  serve  to  show  how  great  may  be 
the  variations  in  the  sinuses  and  nasal  chambers.  Similar 
comparisons  between  the  sphenoidal  and  frontal  sinuses,  and 
the  ethmoidal  and  other  cells,  would  show  as  marked  differ- 
ences. Bilateral  variations  almost  equally  extensive  are  found 
in  the  individual  skull,  except  as  to  the  depth  of  the  face. 
Diagnosis  and  surgical  manipulation  in  such  cases  will  vary  as 
much  as  the  anatomical  structures  differ. 

In  Fig.  85  is  shown  an  antero-posterior  section  illustrating 
the  close  relation  between  the  frontal  and  maxillary  sinuses. 
It  also  shows  that  in  this  instance  fluids  could  (as  they  actually 
did)  pass  from  the  frontal  sinus  and  ethmoidal  cells  into  the 
maxillary  sinus.  Of  the  two  probes  passed  through  the 
ostium  maxillare,  one  goes  directly  through  the  posterior  por- 
tion of  the  hiatus  semilunaris  into  the  middle  meatus,  while  the 
other  (the  vertical  one)  passes  into  the  hiatus  semilunaris, 
then  upward  and  a  little  forward  into  the  frontal  sinus. 

Fig.  86  is  an  anterior  view  of  a  transverse  vertical  section, 
showing  the  lower  portion  of  the  frontal  sinuses  on  both  sides, 
with  a  -probe  passed  from  the  right  sinus  downward  and 
slightly  outward  along  the  hiatus  semilunaris,  and  then 
through  the  ostium  maxillare  into  the  max:illary  sinus.  It 
will  be  noticed  that  there  is  quite  a  difference  in  the  anatomy 
of  the  anterior  ethmoidal  cells  bilaterally. 

Fig.  87  is  a  posterior  view  of  the  same  section  as  Fig  86. 
The  course  of  the  probe  can  be  traced  as  it  passes  downward 
along  the  hiatus  semilunaris,  through  the  ostium  maxillare, 
and  into  the  sinus  without  obstruction.     There  is  a  lack  of 


axatomr'al  \ak  i  atjc  ).\s. 
Fig.  82. 


103 


Posterior  view  of  two  vertical  transverse  sections  made  from  different  skulls  in 
about  the  same  anatomical  region,  showing  great  variations  as  to  the  depth  of  face,  and 
size  and  shape  of  the  maxillary  sinuses  and  nasal  chambers. 


104 


INTERNAL    ANATOMY    OF    THE    FACE. 


bilateral  symmetry  in  the  unciform  process  and  bulla  eth- 
moidalis.  As  this  is  a  section  of  a  negro  skull,  the  great  thick- 
ness of  the  floor  of  the  antrum  is  accounted  for. 

Fig.  88  gives  another  view  of  the  hiatus  semilunaris  leading 
downward  and  backward  from  the  frontal  sinus  into  the  mid- 
dle meatus,  a  portion  of  the  walls  (bulla  ethmoidalis)  covering 
the  middle  ethmoidal  cells  having  been  cut  away. 

Fig.  83. 


A  B 

Posterior  views  of  two  vertical  transverse  sections  inade  from  different  skulls  in  about 
the  same  anatomical  region,  showing  great  variations  as  to  depth  of  face,  and  size  and  shape 
of  nasal  and  maxillary   sinuses. 


Fig.  89  shows  two  hiatuses,  or  infundibula,  leading  directly 
into  the  maxillary  sinus.  Through  the  posterior  hiatus  a 
probe  is  shown,  the  outer  wall  of  the  anterior  one  having  been 
cut  away  in  order  that  a  better  view  could  be  obtained. 

Fig.  90  illustrates  a  vertical  transverse  section,  showing  a 
more  direct  communication  between  the  frontal  and  maxillary 
sinuses  than  do  Figs.  86  and  87.  It  gives  posterior  and  an- 
terior views  of  the  same  section,  A  having  that  portion  of  the 
face  removed  which  extends  back  to  the  premolar  teeth  below, 
and  exposing  the  frontal  sinuses  above.     The  septum  of  the 


ANATOMICAL  VARIATIONS. 
Fig.  84. 


105 


Two   illustrations   from   different   subjects,   showing  great  variations  as   to   depth   and 
size  in  the  external  wall  of  the  nasal  chambers.    A  shows  four  meati. 


io6 


INTERNAL    ANATOMY    OF    THE    FACE. 


nose  is  deflected  and  a  "spur"  reaches  over  to  the  right  turbi- 
nate. The  frontal  sinuses  extend  down  below  the  middle  of 
the  orbit.  Between  them  there  is  an  inter-frontal  cell  extend- 
ing backward  into  the  crista  galli,  as  is  shown  in  B.     A  wire 

Fig.  85. 


f^ 


Anteio  pobterior  section  showing  inner  wall  of  the  orbit,  and  the  maxillary  sinus 
with  two  probes  through  the  ostium  maxillare.  The  conical  elevation  in  the  floor  of 
the  antrum  is  where  a  root  of  a  tooth  has  been  left,  retarding  resorption  in  this  part  of 
the  floor,  in  the  remainder  of  which  the  process  has  been  active. 


passed  downward  from  the  right  frontal  sinus  is  again  seen  in 
the  antrum.  B  shows  the  section  cut  posteriorly  to  the  first 
molar  teeth.  The  frontal  sinuses  extend  outwardly  over  the 
orbits.  The  wire  shown  in  A  is  seen  passing  downward  from 
the  right  frontal  sinus  through  the  infundibulum  and  hiatus 


ANA'I'O.M  UAI.   \AKlATl(li\S. 


107 


semilunaris   and    entering-    tlic    maxillary    sinus    through    the 
ostium  maxillare. 

Fig.  86. 


Anterior  view  of  a  vertical  transverse  section  of  a  negro  skull  between  the  second 
premolar  and  the  first  molar  tooth,  showing  probe  passing  down  through  the  frontal 
sinus,  the  hiatus  semilunaris,  and  ostium  maxillare,  into  the  maxillary  sinus. 


Fig.  87. 


Posterior  view  of  section  shown  in   Fig. 


Fig.  91  shows  an  anterior  view  of  a  vertical  transverse  sec- 
tion in  the  region  of  the  premolar  teeth.  Between  the  orbits 
are  seen  the  anterior  ethmoidal  cells,  and  also  a  sinus  in  the 


I05  INTERNAL   ANATOMY    OF    THE    FACE. 

crista  galli.     In  this  case  both  antra  extend  upward  and  be- 
come common  with  the  ethmoidal  cells  and  frontal  sinuses. 
Fig.  92  gives  a  posterior  view  of  a  vertical  transverse  section 

Fig.  88. 


Interior  view  of  the  outer  wail   of  tlie  nasal  fossa  witli  part  of  the  bone  cut  away  to 
show  the  hiatus  semilunaris  and  the  middle  ethmoidal  cells. 


\  1 


Section  showing  two  hiatuses,  both  leading  directly  into  the  maxillary  sinus.  The 
posterior  hiatus  has  a  probe  passing  through  it,  the  anterior  one  has  the  external  wall 
cut  away  in  order  that  a  better  view  may  be  had. 

cut  in  the  region  of  the  first  molar  teeth  and  through  the 
crista  galli.  The  septum  is  deflected  toward  the  left  side; 
the  right  maxillary  sinus  extends  upward  and  inward,  termi- 
nating in  a  large  opening  into  the  hiatus  semilunaris  without 


ANATOMICAL  VARIATIONS. 


IC9 


Fig.  90. 


Anterior  and  posterior  views  of  a  vertical  transverse  section  in  the  region  between 
the  second  premolar  and  first  molar  teeth,  showing  a  wire  passing  from  the  frontal  sinus 
into  the  maxillary  sinus.  The  frontal  sinus  extended  downward  to  nearly  the  level  (f 
the  upper  portion  of  the   antrum. 


no 


internal  anatomy  of  the  face. 
Fig.  91. 


Anterior  view  of  vertical  transverse  section  in  the  region  of  the  first  molar  teeth, 
showing  anterior  ethmoidal  cells,  and  a  cell  in  the  crista  galli.  The  frontal  sinus  extends 
downward,  becoming  common  with  the  ethmoidal  cells  and  antrum. 

Fig.  92. 


Infraorbital    Sinus. 
Infraorbital  Canal. 


Semilunaris. 


Posterior  view  of  a  vertical  transverse  section  through  the  first  molar  teeth.  The 
right  hiatus  semilunaris  in  this  subject  communicates  with  the  maxillary  sinus  without 
a  true  ostium  maxillare. 


AXATO.MKAL    \AK1AT10XS. 


Ill 


a  true  line  of  demarkation.  The  left  maxillary  sinus  extends 
forward  into  the  infraorbital  ridge,  forming  an  infraorbital 
sinus  somewhat  similar  to  those  shown  in  Figs.  51,  54,  and  79. 
Fig.  93  shows  a  posterior  view  of  a  vertical  transverse  sec- 
tion from  the  skull  of  an  aged  person.  The  fioor  of  the  max- 
illary sinus,  the  nasal  fossae,  and  the  lower  border  of  the 
alveolar  process  are  almost  on  a  horizontal  line.  The  left 
maxillary  sinus  extends  upward  until  it  passes  into  the  frontal 


Fig.  93. 


Posterior  view  of  a  vertical  transverse  section  in  the  region  of  tlie  ostium  maxillare. 
From  the  skull  of  an  aged  person.  The  floor  of  the  nasal  fossae,  the  alveolar  process,  and 
the  floor  of  the  antrum  are  nearly  on  the  same  level.  The  left  maxillary  sinus  extends 
upward  through  the  region  of  the  anterior  ethmoidal  cell  into  the  frontal  sinus  without 
a  line  of  demarkation  between  them. 


In  the  crista  galli  is  seen  a  small  sinus  or  cell  which 

This  last  formation  is 


sinus,   without  any  line  of  demarkation  between  sinuses  or 

cells. 

extends  forward  into  the  frontal  sinus. 

also  shown  in  Figs.  74,  82,  90.  and  91. 

Fig.  94  shows  a  posterior  view  of  a  vertical  transverse  section 
cut  back  of  the  first  molar  teeth.  The  maxillary  sinuses 
are  almost  cuboidal  in  shape  and  extend  down  below  the  fioor 


112 


INTERNAL    ANATOMY    OF   THE    FACE. 


of  the  nasal  fossae  inward  and  toward  the  median  Hne,  out- 
ward into  the  malar  bones,  and  upward  into  the  ethmoidal 
cells.  The  inner  walls  are  not  straight,  as  in  Figs.  25  and  26. 
Starting  at  the  floor  of  the  antrum,  almost  over  the  center 
of  the  dome  of  the  mouth,  the  inner  wall  as  it  extends  upward 

Fig.  94. 


Posterior  view  of  a  vertical  transverse  section  near  the  first  molar  teeth,  showing 
maxillary  sinuses  which  are  nearly  cuboidal  in  shape  and  which  extend  downward  below 
the  floor  of  the  nasal  fossae.  The  nasal  chamber  is  narrow  and  the  walls  dividing  it  from 
the  sinuses  are  concavo-convex  in  their  vertical  direction. 


curves  outwardly,  then  inwardly  to  the  point  at  which  the 
inferior  turbinate  projects  into  the  nasal  chamber.  This  for- 
mation leaves  a  very  narrow  or  contracted  nasal  cavity,  a 
conformation  also  shown  in  B,  Fig.  83. 


E1--FECT.S    (JF    rAlll()I.U(;iC.\l.     COXIJITIONS.  II3 


EFFECTS  OF  PATHOLOGICAL  CONDITIONS  IN 

THE  REGION  OF  THE  HIATUS 

SEMILUNARIS. 


Pathological      Conditions       of     the      Bulla       Ethmoidalis. 

Through  pathological  increase  in  the  size  of  tJie  bulla  eth- 
moidalis, disturbances  may  be  caused  in  the  anterior  and  su- 
perior portion  of  the  nasal  chamber,  in  the  frontal  sinus,  and 
in  the  antrum  of  Highmore,  for  by  its  enlargement  toward 
the  median  line  it  presses  toward  and  against  the  septum, 
closing  the  space  of  the  nasal  fossae.  If  this  enlargement  is 
downward  it  presses  more  upon  the  unciform  process  and  into 
the  hiatus  semilunaris,  closing  it  and  preventing  the  passage 
of  fluids  from  the  frontal  sinuses  and  the  anterior  ethmoidal 
cells  into  the  posterior  portion  of  the  middle  meatus,  and 
forcing  them  to  enter  the  maxillary  sinus.  Through  general 
inflammation  of  the  parts  there  may  result  an  excess  of  fluids 
which  cannot  find  exit.  This  would  interfere  with  the  vitality 
of  the  teeth  through  pressure  upon  the  nerves  and  vessels 
passing  through  the  maxillary  sinus.  It  would  cause  a  feeling 
of  fullness  of  all  the  anterior  cells,  as  well  as  the  frontal  sinus, 
and  might  even  set  up  disturbance  in  the  anterior  portion  of 
the  brain-case. 

Fig"-  95-  ^  shows  a  view  of  the  nasal  septum  as  seen 
from  the  left  nasal  chamber.  An  opening  in  the  septum  ex- 
poses to  view  the  bulla  ethmoidalis  and  the  ethmoidal  cells. 
This  opening  resulted  from  resorption  caused  by  pressure 
due  to  the  deflection  of  the  septum  and  the  enlargement 
of  the  bulla  downward  near  the  unciform  process.  We  have 
here  illustrated  an  example  showing  how  enlargement  of  this 


114 


INTERNAL    ANATOMY    OF    THE    FACE. 


Structure  may  be  an  important  factor  in  causing  various  dis- 
eases of  this  region,  including  those  of  the  maxillary  and 
frontal  sinuses. 

B,  Fig.  95,  gives  a  view  of  the  same  subject  as  A,  from  the 
same  direction,  but  with  the  septum  removed,  exposing  the 
inner  surface  of  the  outer  wall  of  the  right  nasal  chamber.  Of 
the  two  openings  into  the  maxillary  sinus  as  seen  in  this  pic- 

FiG.  95. 


A,  the  left  side  of  the  nasal  septum,  showing  a  pathological  opening  opposite  the 
bulla  ethmoidalis.  B,  same  specimen  with  the  septum  removed,  showing  abnormal 
opening  into  the  maxillary  sinus. 


ture,  the  anterior  one  is  normal,  the  posterior  is  abnormal. 
This  abnormal  opening  and  the  loss  of  the  greater  portion 
of  the  middle  turbinate  were  caused  by  resorption  due  to  the 
pressure  of  the  bulla  ethmoidalis  before  referred  to. 

The  effect  of  blocking  up  the  hiatus  semilunaris  in  causing 
the  secondary  or  associated  openings  between  the  antrum  and 
the  nasal  chambers  is  also  shown  in  Fig.  97. 

Fig.  96  shows  two  pictures  from  the  left  side  of  the  same 
skull  shown  in  Fig.  95.  In  B  the  middle  turbinate  is  in  posi- 
tion.    The  abnormal  opening"  into  the  nasal  chamber,  seen 


EFl'-)':CTS    OF    I'A'niOI.OOK'AI-    CONDITIOiNS. 


115 


near  the  center  of  the  picture,  was  probably  the  result  of  the 
closure  of  the  hiatus  semilunaris,  shown  in  A.  In  this  the 
middle  and  a  portion  of  the  superior  turbinate  are  cut  loose  and 
turned  upward,  to  expose  the  bulla  ethmoidalis  extending 
downward  and  closing  the  hiatus.  This  closure  would  compel 
the  tluids  from  the  frontal  sinus  and  the  anterior  and  middle 
ethmoidal  cells  to  pass  into  the  maxillary  sinus. 

Fig.  96. 


// 


.X-:^'  .^^«*^l^*tB«»<^ 


A 


B 


Two  ijictures  of  the  left  nasal  chamber  from  the  same  subject  as  Fig.  95.  B,  showing 
an  abnormal  opening  into  the  maxillary  sinus.  A,  same  specimen  as  B  with  a  portion  of 
the  middle  and  superior  turbinates  cut  loose  and  turned  up. 

Fig.  97  shows  two  antero-posterior  sections  from  another 
skull  in  which  the  bulla  ethmoidalis  has  become  enlarged. 
Section  B  has  the  outer  wall  of  the  maxillary  sinus  re- 
moved, showing  the  inner  wall  with  two  outlets  at  its  upper 
margin.  The  anterior  opening  is  the  normal  ostium  maxil- 
lare.  The  posterior  one  is  abnormal  and  similar  to  those 
shown  in  Figs.  95  and  96,  but  in  this  case  the  opening  is 
nearer  to  the  roof  of  the  sinus.  Section  A  is  cut  from  the 
inner  side  of  B. 

Fig.  98  illustrates  the  same  sections  as  Fig.  97,  with  section 
B  turned  round  to  the  left  side  of  the  other.     The  illustration 


ii6 


INTERNAL    ANATOMY    OF    THE    FACE, 


affords  a  view  of  the  nasal  chamber  divided  through  the 
hiatus  semilunaris,  the  bulla  ethmoidalis,  and  the  posterior 
ethmoidal  cells.  Section  B  shows  the  outer  wall  of  the  nasal 
chamber  with  a  greater  portion  of  the  turbinate  bones  re- 
moved. Section  A  shows  the  septum  of  the  nose.  The 
two  together  give  a  very  clear  idea  of  the  character  of  the 
hiatus  semilunaris  and  the  bulla  ethmoidalis.  In  this  case  the 
bulla  is  very  large  and  extends  downward  and  forward,  closing 
the  hiatus.     The  illustration  is  taken  from  a  dried  specimen. 

Fig.  97. 


A  B 

Antero-posterior  sections,  A  through  the  nasal  chamber,  B  through  the  maxillary 
sinus.  The  former  shows  a  divided  bulla  ethmoidalis,  the  latter  shows  two  ostia 
maxillaria. 


showing  an  incomplete  closure,  which  in  the  recent  state 
must  have  been  complete.  This  would  have  caused  the  fluids 
from  the  frontal  sinus  and  the  ethmoidal  cells  anterior  to  the 
closure  to  be  directed  into  the  antrum,  as  the  ostium  maxil- 
lare  is  also  anterior  to  the  bulla.  (The  maxillary  sinus  would 
become  engorged  with  their  fluids,  which  would  naturally 
work  through  the  walls  in  the  direction  of  the  least  resist- 
ance,— in  this  case  at  the  abnormal  opening  shown  in  Fig.  97.) 
These  sections  also  illustrate  a  condition  sometimes  met  with, 
when  the  hard  palate  is  unusually  flat.  In  such  cases  the 
floor  of  the  nose,  instead  of  being  horizontal,  is  depressed 
about  the  middle,  giving  a  concavity  which  affords  a  lodgment 


EFFECTS    OF    PATHOLOGICAL    CONDITIONS. 


117 


for  inspissated  mucus.  The  same  condition  may  also  occur  in 
the  floor  of  the  nose,  when  the  inferior  meatus  is  occluded,  as 
shown  in  Fig.  67,  and  is  also  found  in  other  spaces  in  and 
about  the  nasal  chambers.  Collections  of  this  character  often 
produce  irritation  of  the  mucous  membrane  interfering  with 
the  nourishment  of  the  bone  beneath,  and  at  times  causing  a 
necrotic  condition. 

Occlusion  of  the  Outlets  of  the  Frontal  Sinus.     In  Fig.  99, 
B  shows  a  horizontal  section  through  the  anterior  fossae  of  the 

Fig.  98. 


Antero-posterior  sections,  showing  where  they  were  cut  apart  through  the  frontal 
sinus,  the  hiatus  semilunaris,  the  bulla  ethmoidalis,  and  the  posterior  ethmoidal  cells. 

brain-case  and  through  the  frontal  sinuses,  from  one  of  which 
there  has  been  no  foramen  of  exit,  an  example  of  unilateral 
occlusion.  A  gives  a  view  of  the  roofs  of  the  maxillary  sinuses 
and  of  the  nasal  chamber. 

The  section  shown  in  Fig.  100  is  made  from  the  same  sub- 
ject as  Fig.  99,  one  inch  below  B,  Fig.  99.  It  shows  the  down- 
ward excavation  which  has  occurred  in  the  occluded  sinus. 
In  the  lower  surface,  A,  of  the  specimen  is  shown  the  excava- 
tion extending  in  the  direction  of  the  nasal  spine.  There  are 
marked  irregularities  of  the  ethmoidal  cells  of  the  two  sides. 

Fig.  loi  also  illustrates  unilateral  occlusion.  This  section 
exhibits  the  floor  of  the  brain-case,   showing  a  perforation 


ii8 


INTERNAL   ANATOMY   OF   THE    FACE. 


Fig. 


A  shows  the  roof  of  the  nasal  chamber  and  the  maxillary  sinus,  B  the  floor  of  the 
anterior  fossa  of  the  brain-case  and  part  of  the  frontal  sinuses,  to  one  of  which  there  is 
no  foramen  of  exit. 

Fig.  ioo. 
A 


Horizontal  sections  in   same   subject  as   Fig.   99,   showing   surfaces   cut   through  the 
middle  of  Ihe  orbits  and  the  upper  part  of  the  nasal  chamber. 


F.i'FKcrs  t)i    I'Ai  iKii.dCicAi.  (( )N'i)rrioxs.  119 

at  the  point  indicated  by  tlie  thread  ])assin,L;-  throngli  it. 
It  is  reasonal)le  to  snppose  that  the  retained  llnids  have 
burrowed  throni;h  the  cril)riform  plate,  causing  the  perfora- 
tion. The  crista  galH  in  the  specimen,  although  not  clearly 
shown  in  the  picture,  is  bent  downward  until  almost  flat  by 
what  has  evidently  been  a  cyst  or  tumor  within  the  brain-case 
in  this  region.  Unfortunately,  the  w-riter  was  unable  to  ol)tain 
ante-mortem  or  clear  post-mortem  notes  of  these  two  cases. 
It  might  be  supposed,  how^ever,  that  the  patients  presented 
cerebral  symptoms.  In  confirmation  of  this  idea,  there  w-as 
evidence  in  the  condition  of  the  skulls  that  there  had  been  a 
post-mortem  examination  of  them. 

Fig.  ioi. 


Horizontal  section,  showing  the  floor  of  the  anterior  fossa  of  the  brain-case  and  part 
of  the  frontal  sinuses.  The  right  sinus  had  no  outlet  into  the  hiatus  semilunaris,  but 
had  an  outlet  into  the  anterior  fossa  of  the  brain-case. 

Fig.  102  is  from  the  same  specimen  as  Fig.  loi.  It  shows 
the  effects  of  the  encroachment  of  the  inflammatory  and  ne- 
crotic condition  upon  the  internal  w-all  of  the  orbit. 

Fig.  103,  from  the  same  specimen,  shows  a  horizontal  sec- 
tion made  through  the  ethmoidal  cells,  the  nasal  fossae,  etc., 
along  the  line  indicated  in  Fig.  102.  The  two  faces  of  the 
specimen  show  clearly  the  broken-down  condition  produced 
in  the  track  of  the  disease.  The  abnormal  arrangement  of 
the  cells  becomes  especially  apparent  when  compared  with 
the  typical  arrangement  show^n  in  Fig.  63. 

Obstruction  of  Fluids.  There  is  a  fundamental  law^  of  sur- 
gery that,  wdierever  an  obstruction   of  any  of  the  passages 


120 


INTERNAL    ANATOMY    OF    THE    FACE. 


within  the  body  exists,  it  should  be  removed,  and  if  possible 
the  course  of  fluids  be  re-established  in  their  normal  channels 


Fig.  102. 


From  same  subject  as  Fig.   loi.     View  showing-  diseased  condition  of  the  inner  wall 
of  the  orbit. 

Fig.  103. 


From   same   subject   as    Figs.    loi   and    102.     Horizontal   division   through   the   orbit 
and  ethmoidal  cells,  showing   the  diseased  condition  of  these  cells. 


or  conduits.  If  the  hiatus  semilunaris,  which  is  the  outlet  of 
the  fluids  of  the  frontal  sinus,  becomes  closed  in  any  portion, 
or  at  the  inlets,  by  bony  or  other  growths,  it  is  good  and 


EFFECTS    OF    PATHOLOGICAL    CONDITIONS.  121 

proper  surgery  to  remove  these  obstructions.  If  fluids  from 
the  various  sinuses  and  cehs  are  allowed  to  accumulate  in  the 
maxillary  sinus  without  opportunity  to  escape,  the  teeth  and 
the  alveolar  process  are  liable  to  become  involved,  by  the 
teeth  becoming  sore  upon  pressure,  by  being  loosened,  or  by 
pus  or  other  fluids  passing  down  between  them  and  their 
sockets.  In  such  a  case,  after  the  failure  of  local  treatment, 
the  patient  may  be  referred  to  a  rhinologist.  Sometimes  the 
surgeon,  baffled  by  the  nasal  and  antral  troubles,  will  make 
an  outlet  from  the  antrum  into  the  mouth,  to  give  egress  to 
the  confined  fluids,  infected  or  otherwise.  These  should  pass 
from  the  superior  and  anterior  portion  of  the  nose  and  frontal 
sinuses  into  the  middle  meatus.  The  mouth  should,  by  all 
means,  be  kept  free  from  these  foul  discharges,  and  such 
proper  surgical  procedure  instituted  as  will  restore  the  natural 
outlets  without  infecting  the  oral  cavity. 


122  INTERNAL    ANATOMY    OF    THE    FACE. 


IMPACTED  TEETH. 


At  the  meeting  of  the  American  Dental  Association  for 
1895,  the  writer  gave  illustrations  of  a  number  of  impacted 
teeth.*  Since  that  time  he  has,  in  examining  different  pa- 
tients, seen  other  examples  of  nearly  all  the  forms  of  impaction 
then  described. 

It  is  evident  that  there  is  an  active  process,  varying  in  de- 
gree according  to  age,  going  on  in  the  osseous  surroundings 
of  the  teeth  from  the  time  of  the  development  of  the  first 
tooth  until  the  eruption  of  the  last  molar;  even  then  it  does 
not  necessarily  cease,  for  as  the  teeth  are  worn  down  they 
become  more  or  less  diseased,  then  lost,  after  which  the  alveo- 
lar process  is  resorbed,  so  that  in  old  age  the  jaws  take  the 
shape  shown  in  B,  Figs.  150  and  151. 

Interference  with  Development.  If  the  action  of  this 
process  be  interfered  with  during  the  development  and  erup- 
tion of  the  teeth,  their  normal  arrangement  will  be  modified 
in  proportion.  Interferences  causing  impaction  can  often  be 
attributed  to  many  diseases  of  children,  such  as  scarlet  fever 
and  other  constitutional  disturbances  which  cause  inflamma- 
tory conditions  in  and  about  the  jaws. 

Fig.  1047  gives  a  general  idea  of  the  arrangement  and  posi- 
tion of  the  teeth,  deciduous  and  permanent,  and  of  their  rela- 
tions, about  the  sixth  or  seventh  year.  The  external  walls  of 
the  alveolar  process  of  the  upper  and  lower  jaws  have  been 
removed,  together  with  some  of  the  cancellated  tissue,  expos- 
ing the  roots  of  the  deciduous  teeth  and  the  crowns  of  the 

*See  Dental  Cosmos,  January,  1896. 
tFig.  104  is  a  repetition  of  Fig.  29. 


IMPACTED    TEETH.  1 23 

permanent  ones.  It  will  l)e  again  noticed  that  at  this  age 
nearly  all  of  the  space  of  the  maxillary  bone  is  occupied  by 
the  dental  organs,  there  being  but  little  room  for  the  maxil- 
lary sinus.  It  would  seem  clear  that  by  interference  with  the 
natural  processes  at  this  period  of  life,  the  permanent  teeth 
can  be  deflected  or  detained  from  assuming  their  normal  posi- 
tions, thus  modifying  the  maxillary  sinus  or  nasal  chamber. 
^^'hen  these  chambers  are  changed  in  form,  size,  or  position, 
associated  cavities  and  adjoining  structures  will  also  be 
changed.  The  shape  of  the  orbit  may  also  be  modified  to 
such  an  extent  that  the  eye  may  be  affected,  making  it  my- 
opic or  hypermetropic. 

Nutritional  Changes.  There  are  two  opposite  processes 
associated  with  inflammation  within  the  jaws,  one  destructive 
or  suppurative,  causing  the  breaking  down  of  the  tissue;  the 
other,  a  constructive  or  building  up  and  hardening  process, 
through  which  the  cancellated  tissue  is  transformed  into  hard 
and  dense  bone.  (See  Figs.  i6  and  121.)  Through  undue 
hardening  of  the  bone  before  complete  eruption  of  the  teeth, 
they  become  incased  with  their  capsules  in  the  surrounding 
bone,  under  which  circumstance  it  is  impossible  for  the  erup- 
tive force  to  carry  them  into  their  proper  positions.  They 
are  often  held  in  the  place  of  development,  or  pushed  in  the 
direction  of  the  least  resistance,  until  resorption  of  the  bone- 
tissue  occurs,  when  they  usually  make  their  appearance  in 
an  abnormal  position. 

Supernumerary  Teeth.  The  development  of  a  supernu- 
merary tooth  or  teeth  may  also  cause  impaction  of  a  normal 
tooth.  Two  marked  cases  have  come  under  the  writer's  ob- 
servation, the  first  in  a  skull  belonging  to  Dr.  Kirk's  collec- 
tion, where  thirteen  small  supernumerary  teeth  are  developed 
in  the  position  of  the  root  of  the  left  upper  central  incisor, 
which  was  found,  upon  dissection,  to  be  impacted  between 
the  floor  of  the  nose  and  the  roof  of  the  mouth.  The  other 
case  was  in  the  mouth  of  a  patient  of  Dr.  Huey's,  of  Phila- 
delphia,  where   thirty-five   small    supernumerarv    teeth   were 


124 


INTERNAL    ANATOMY    OF    THE    FACE. 


found  within  the  alveolar  process,  in  the  space  which  should 
have  held  the  left  central  incisor.  After  removing  the  super- 
numerary teeth,  the  permanent  normal  incisor  could  be  seen 
resting  between  the  plates  of  bone  forming  the  roof  of  the 
mouth  and  the  floor  of  the  nose. 

In  Fig.  104*  the  crown  of  the  upper  first  molar  is  visible. 
The  position  of  the  germs  of  the  second  and  third  molars  is 

Fig.   104. 


Skull  of  a  child  about   six  years  of  age,   showing  all  the  deciduous  teeth  in  position 
and  the  developing  permanent  teeth. 

higher  up  and  further  back,  therefore  they  must  be  close  to 
the  under  surface  and  posterior  portion  of  the  orbit.  This 
was  interestingly  demonstrated  by  a  patient  referred  to  the 
Department  of  Dentistry  of  the  University  of  Pennsylvania, 
who  had  an  impacted  upper  third  molar,  the  crown  of  which 
was  in  the  upper  portion  of  the  posterior  wall  of  the  max- 
illary sinus. 

*For  further  description  of  this  iUustration,  see  Fig.  29,  of  which  it  is  a 
repetition. 


IMPACTED    TEETH. 


125 


Fig.  105  is  a  photograph  h'om  the  skull  in  Dr.  Kirk's  collec- 
tion. It  affords  also  a  good  idea  of  the  general  condition 
found  in  the  mouth  of  Dr.  Huey's  patient.  The  permanent 
central  tooth  was  not  removed  with  the  supernumerary  teeth 
in  this  case,  as  Dr.  Huey  and  the  writer  had  some  hopes  that 
it  would  assume  its  normal  place  with  the  other  teeth.  Six 
months   after   the   operation   the   tooth   had   advanced   more 


An  odontoma  and  an  impacted  central  incisor. 


than  half  its  length,  and  at  this  writing,  eighteen  months 
afterward,  it  is  about  in  its  normal  position. 

Fig.  106  is  an  illustration  of  the  central  incisor  and  super- 
numerary teeth  taken  from  the  skull  shown  in  Fig.  105. 

Fig.  107  is  an  illustration  made  from  a  section  which 
was  constructed  in  order  to  give  an  idea  of  the  position 
of  the  tooth  in  this  patient's  mouth.  If  this  crown,  as  shown 
in  the  illustration,  had  roots  of  normal  length,  they  would 
extend  back  across  the  spheno-maxillary  space,  the  points  of 


126  INTERNAL    ANATOMY    OF    THE    FACE. 

the  roots  would  be  near  the  sphenoidal  sinus,  and  the  roots 
would  more  than  likely  be  covered  by  a  thin  lamina  of  bone 
developed  from  the  maxilla.  In  cases  where  teeth  have  been 
found  impacted  in  the  upper  part  of  the  maxilla,  similar  to' 
that  shown  in  this  illustration,  they  are  commonly  spoken  of 
as  having  passed  upward.  This,  in  the  opinion  of  the  writer, 
is  incorrect.  It  is  more  likely  that  many  of  the  teeth  so  found 
impacted  have  never  passed  down  from  their  place  of  develop- 
ment. In  this  particular  case,  through  some  inflammatory 
process,   the  tooth  and  its  capsule  became  adherent  to  the 

Fig.  io5. 


//^r.j- 


Views  of  the  impacted  tooth  and  odontoma  removed  from  the  jaw  illustrated  in 
Fig.  105. 

posterior  wall  of  the  maxilla,  the  intrinsic  force  being  insufli- 
cient  to  force  the  tooth  into  proper  position  at  the  time  it 
should  have  made  its  descent.  It  is  somewhat  analogous  to 
an  adherent  testicle  in  the  abdominal  cavity  or  in  the  inguinal 
canal.  There  is  no  more  reason  to  think  that  the  tooth  passes 
upward  than  that  the  testicle  passes  up  from  the  scrotum  into 
the  inguinal  canal  or  abdominal  cavity. 

Fig.  108  represents  three  impacted  permanent  teeth,  a  cen- 
tral, lateral,  and  canine,  which  were  removed  from  a  living 
subject  in  1 89 1. 

Fig.  109  is  taken  from  a  specimen  belonging  to  Professor 
James  Truman's  collection.  It  shows  an  impacted  right  ca- 
nine; the  external  bone  has  been  cut  away,  exposing  the  tooth 


IMl'A(TI-:i)    TKIiTIl. 


12: 


and  its  root.  The  tooth  is  a  little  helow  the  place  of  develop- 
ment. The  apex  is  curved  forward  and  inward,  the  inward 
portion  passing  just  into  the  nasal  chamber  as  shown  in  Fig. 
107.  A  little  external  to  the  apex  of  the  root  is  an  opening 
into  the  maxillary  sinus. 

Fig.  107. 


An  illustration  representing  an  impacted  toiUh  in  the  posterior  wall  of   the  maxillary 
sinns. 

Fig.  108. 


^.^        Wi 


A  central,  a  lateral,  and  a  canine  tooth  removed  from  the  maxillary  sinus  of  a  patient 
who  had  been  suffering  with  neuralgia. 

Fig.  no  is  a  view  from  the  other  side  of  the  specimen  seen 
in  Fig.  109,  showing  the  apex  of  the  impacted  canine  in  the 
external  wall  of  the  nasal  cavity. 

Fig.  37  show^s  an  impacted  canine  with  its  crowm  immedi- 
ately over  the  alveolus  of  the  right  central,  the  root  passing 
upw^ard  and  backward. 

Loss  of  Teeth   through    Impaction.     Fig.    in    shows    two 


128 


INTERNAL    ANATOMY    OF   THE    FACE. 
Fig.  109. 


An  impacted  canine  tooth  with  the  apex  of  the  root  within  the  nasal  fossa. 


Fig.  1 10. 


Apex  of  an  Impacted  Root. 


External    wall    of   the    nasal    chamber,    seen    from   the    inside,    showing    the    apex   of 
the   impacted  canine  tooth  illustrated    in   Fig.   109. 


IMPACTED    TEETH. 


129 


canines  impacted  in  the  upper  jaw,  lying  at  nearly  right  angles 
to  each  other.  They  were  entirely  covered  with  bone,  and 
were  exposed  by  a  surgical  bur.  The  end  of  the  root  of  the 
right  canine  is  somewhat  curved.  There  is  only  a  slight  layer 
of  bone  between  it  and  the  floor  of  the  sinus.  This  layer  of 
bone  is  perforated  by  three  small  openings.  This  malposi- 
tion caused  the  loss  of  the  left  first  and  second  premolars, 
also  of  the  right  first  premolar. 

Fig.  III. 


Two  impacted  canine  teeth.  Their  malposition  caused  the  loss  of  the  left  first  and 
second  premolars,  also  the  loss  of  the  right  first  premolar. 

Fig.  112  is  a  posterior  view  of  a  transverse  vertical  section 
of  a  face,  made  in  the  region  of  the  first  premolar  teeth.  Be- 
sides other  interesting  points,  the  crown  of  the  canine  tooth 
has  penetrated  the  palatal  surface  of  the  mouth  and  the  root  is 
within  the  anterior  portion  of  the  antrum.  Before  the  dissec- 
tion was  made,  the  root  was  covered  with  a  thin  lamina  of 
bone.  Similar  conditions  are  often  found,  involving  not 
only  the  canine  tooth,  but  also  the  third  molar,  and  occa- 
sionally other  teeth,  which  often  remain  in  such  positions  for 
vears  without  giving  anv  trouble  until  after  middle  life,  when 


130 


INTERNAL   ANATOMY    OF   THE    FACE. 


by  natural  resorption  of  the  bone  the  crown  and  root  become 
exposed  within  the  antrum  or  nasal  chamber,  at  which  time 
they  may  cause  some  disturbance. 

Fig.  113  illustrates  an  impacted  left  central  incisor,  which 
lies  diagonally  across  the  alveolar  process,  with  the  apex  of 
the  root  near  the  outer  side  of  the  left  anterior  nares.  The 
crown  passes  across  the  anterior  palatine  fossa.     Impaction  of 

Fig.  112. 


Root  of  canine  tooth. 


Crown  of  canine  tooth. 


An  impacted  canine  tooth,  the  crown  in  the  roof  of  the  mouth,  the  greater  portion 
of  the  root  in  the  maxillary  sinus. 


this  kind  would  more  than  likely  interfere  with  the  true  func- 
tion of  the  nerves  and  vessels  passing  through  this  fossa. 

Fig.  114  illustrates  a  supernumerary  lateral  incisor  impacted 
immediately  below  the  floor  of  the  nose.  There  was  no  en- 
largement of  the  external  plates  of  the  incisor  fossa,  the  floor 
of  the  nose,  or  the  roof  of  the  mouth.  The  tooth  was  acci- 
dentally discovered  when  cutting  the  bone  transversely. 

Fig.  115  exhibits  an  impacted  and  misplaced  third  molar. 
The  occluding  surface  of  the  molar  was  even  with  the  external 


IMPACTED    TKKTII. 


131 


plate  of  the  alveolar  process,  the  roots  being  compressed  and 
somewhat   shorter  than  normal.     A  complete  thin  layer  of 

Fig.  113. 


An  impacted  central  incisor,   with  the  crown  partly  in  the  anterior  palatine  fossae. 

Fig.  114. 


An  impacted   supernumerary  tooth. 


132 


INTERNAL    ANATOMY    OF    THE    FACE. 


bone  made  a  conical-shaped  partition  between  the  tooth 
sockets  and  the  sinus.  A  similar  condition  existed  on  the  op- 
posite side  of  the  jaw. 

Fig.   II-. 


An  impacted  upper  third  molar.     A  similar  condition  is  found  on  the  opposite  side 
of  the  skull. 

Fig.  i-i6. 


An  impacted  lower  third  molar. 


Fig.  ii6  exhibits  an  impacted  lower  third  molar  in  the 
ramus  of  the  jaw  just  below  the  anterior  portion  of  the  sigmoid 
notch,  the  tooth  being  inverted.  In  this  case  the  capsule  of 
the  germ  of  the  tooth  became  adherent  to  the  walls  of  the  jaw, 


IMPACTED   TEETH. 


133 


and  lost  its  position  within  the  forming  cancellated  tissue, 
when  the  body  of  the  jaw  grew  downward  and  forward. 

Fig.  117  illustrates  the  most  common  kind  of  impacted 
lower  third  molar  teeth.  They  often  give  great  trouble  by 
irritating  the  inferior  dental  nerve.  They  may  also  cause  an 
inflammatory  condition  in  this  region,  and  the  cellulitis  may 


'^ 


Fig.  117. 


•    /^ 


31^      4\ 


rTT\ 


A  common  form  of  impacted  lower  third  molars. 

extend  to  the  temporo-mandibular  articulation  and  the  base 
of  the  tongue. 

Fig.  118  represents  a  similar  impaction.  In  B  the  external 
portion  of  the  bone  covering  the  tooth  has  been  removed, 
and  in  A  the  internal  portion.  In  both  cases  it  will  be  ob- 
served that  the  inferior  dental  canal  is  encroached  upon.  It 
is  often  necessary  to  cut  away  a  portion  of  the  bone  with  the 
surgical  engine  before  a  tooth  so  situated  can  be  removed. 


134 


INTERNAL    ANATOMY    OF    THE    FACE. 


Impaction  Causing  Resorption  of  Adjoining  Tooth.  Fig.  119 
gives  two  views  of  an  impacted  third  molar.  In  A  the  tooth 
is  in  position  as  discovered  when  the  cap  of  bone  was  removed; 
in  B  the  tooth  is  rolled  out  of  its  socket,  showing  its  inner 
surface.  The  bed  of  the  tooth  is  also  seen.  The  second  molar 
is  a  pulpless  tooth,  the  distal  root  of  which  shows  where  the 
impacted  tooth  has  pressed  against  it,  causing  the  resorption 

Fig.  118. 


^ 


jg^<\ 


Side  view  of  two   impacted  lower  third   molars,  the   bone  having   been  removed  in 
order  to  expose  the  roots. 

of  a  portion  of  the  root  until  the  pulp-canal  was  fully  exposed, 
which  must  have  caused  neuralgia.  The  roots  of  the  impacted 
tooth  have  a  slight  curve  inward  at  their  points;  the  con- 
cavity fits  immediately  over  the  inferior  dental  nerve,  and  it  has 
probably  caused  pain  by  pressure.  The  ends  of  the  roots  are 
not  fully  formed,  the  apical  openings  being  large.  It  will  also 
be  noticed  that  the  roots  of  the  teeth  in  the  jaw  are  longer 


IMPACTi:i)    ■\\AV\li. 


135 


than  usual,  that  of  the  canine,  for  example,  passing  below  and 

external  to  the  nerve. 

Fig.  119. 


B 

Two  views  of  an  impacted  lower  third  molar.  In  position  in  A;  in  B  the  tooth  is 
turned  out  of  its  pocket.  Part  of  the  distal  root  of  the  second  molar  has  been  resorbed, 
exposing  the  root-canal,  more  than  likely  causing  the  devitalization  of  the  tooth  and 
thus  producing  neuralgia,  induced  by  the  pressure  from  the  impacted  tooth. 


136  INTERNAL   ANATOMY    OF   THE    FACE. 

Fig.  120  represents  another  impacted  third  molar,  situated 
on  the  inner  side  of  the  jaw  and  pointing  sHghtly  downward. 
The  distal  root  of  the  second  molar  is  slightly  resorbed.  Upon 
uncovering  the  tooth  and  taking  it  from  its  bed,  it  was  fomid 
to  be  incased  in  a  thin  shell  of  bone,  as  though  the  dentinal 
sack  had  ossified  separately  around  the  tooth.  The  inner 
portion  of  the  shell  is  still  in  position;  the  nerve  and  its  ac- 
companying tissue  are  seen  passing  into  the  inferior  dental 
foramen  and  immediately  under  or  against  the  shell.  Here 
again  must  have  been  an  obscure  cause  of  neuralgia. 

Fig.  121  illustrates  the  right  and  left  halves  of  the  lower 
jaw,  A  showing  the  internal  surface  of  the  right  half,  while 
B  shows  the  external  surface  of  the  left  half.  In  the 
former  we  find  the  roots  of  the  third  molar  curved  backward 
at  almost  a  right  angle,  and  enlarged  by  an  abnormal  deposit 
of  cementum  until  the  independent  character  of  the  roots  is 
lost,  the  two  being  fused  together. 

B  shows  an  impacted  tooth  pushing  directly  against  the 
tooth  in  front  of  it.  The  roots  of  this  tooth  have  also  become 
much  enlarged  by  deposit  of  cementum,  while  the  surround- 
ing bone  is  thickened  and  grown  more  compact. 

Extraction.  It  would  have  been  almost  impossible  to  ex- 
tract either  of  the  two  last  named  third  molars  without  frac- 
turing the  jaw,  unless  the  consolidated  portion  of  bone  over 
the  roots  of  the  teeth  had  been  first  removed.  In  a  case  of  this 
kind,  it  is  much  better  to  use  the  surgical  engine  bur  than  to 
cut  or  break  the  parts  away  with  chisel  or  forceps.  A  frac- 
ture at  this  point  will  cause  serious  results;  the  mylo-hyoid 
artery  is  liable  to  be  lacerated  or  even  severed,  and  the  hem- 
orrhage is  difficult  to  control.  It  is  not  easy  to  keep  the 
region  clean  or  aseptic,  and  the  consequent  inflammation  will 
often  interfere  with  free  movement  of  the  jaws  in  degluti- 
tion, speech,  etc.     The  glottis  even  may  become  closed. 

Diagnosis.  Impacted  teeth  are  frequently  the  obscure  or 
hidden  cause  of  various  diseases  about  the  mouth  and  jaws. 
There  is  often  no  external  evidence  of  their  impaction;    pa- 


IMPACTED    TEETH. 
Fig.    120. 


U7 


Two   views   of   an   impacted   lower   third   molar.     In   A   it   is   in   position;   in   B   it  is 
turned   out  of  its  pocket. 


138 


INTERNAL    ANATOMY    OF    THE    FACE. 


tients  may  even  claim  that  the  teeth  which  camiot  be  seen 
have  been  extracted.  The  use  of  the  X  ray  as  a  means  of 
diagnosing  such  cases  has  not  been  as  successful  as  the  writer 

Fig.  121. 


OL 


B 

An  impacted  lower  third  molar  and  a  lower  third  molar  with  curved  and  thickened 
root,  both  belonging  to  the  same  jaw.  The  bone  is  much  more  compact  than  normal 
bone. 


iMi'ACTKi)  'ri-:i':'iii.  139 

had  hoped  it  would  be.  Impacted  incisors  arc  Hable  to  give 
trouble  in  the  nose  or  to  produce  neuralgia  by  the  tooth 
pressing  the  spheno-palatine  nerve  as  it  passes  through  the 
anterior  palatine  fossa.  Occasionally  they  cause  a  partial  sep- 
aration between  the  septum  and  the  floor  of  the  nose.  Im- 
pacted teeth  may  become  either  partly  lodged  in  the  inferior 
meatus  of  the  nose,  sometimes  causing  the  closure  of  the 
lower  portipn  of  the  lachrymal  duct,  or  they  may  lie  hori- 
zontally across  the  roots  of  the  incisors,  especially  of  the  lat- 
eral, or  the  roots  of  the  premolars,  causing  the  devitalization 
of  these  teeth.  Impacted  upper  third  molars  are  liable  to 
interfere  with  the  nerves  and  vessels  in  the  floor  of  the  an- 
trum, near  where  they  pass  through  the  posterior  dental 
foramina  into  the  sinus.  They  may  also  cause  an  enlarge- 
ment of  the  tuberosity  outwardly  until  it  interferes  with  the 
ramus  of  the  lower  jaw,  and  produces  a  cellulitis  which  may 
extend  to  the  temporo-mandibular  articulation,  causing  false 
ankylosis. 

Neuralgia.  The  three  impacted  teeth  shown  in  Fig.  108 
caused  a  bafiling  case  of  facial  neuralgia  until  they  were  found 
and  removed.  The  patient  was  past  middle  life  and  had  suf- 
fered from  neuralgia.  He  had  no  teeth  in  the  alveolar  process 
of  the  right  maxilla,  the  region  of  pain,  almost  all  of  them 
having  been  extracted  in  the  hope  of  giving  relief.  The 
antrum  was  opened  by  the  late  Professor  Garretson  and  the 
writer  in  search  of  the  cause.  It  was  somewhat  surprising  to 
see  three  crowns  protruding  into  the  sinus,  the  roots  being  im- 
bedded in  the  inner  anterior  angle  of  the  w^all  of  the  antrum. 
After  the  teeth  were  extracted  by  small  forceps  the  parts  were 
treated  in  the  usual  way,  with  relief  and  subsequent  cure.  The 
crowns  were  in  normal  shape  and  quite  healthy,  the  roots  more 
or  less  defective.  The  pulps  were  alive,  and  it  is  probable  that 
the  nerves  were  impinged  upon  at  the  points  of  the  roots,  thus 
causing  the  pain.  The  writer  has  seen  several  cases  where  a 
greater  portion  of  the  root  of  a  single  tooth  was  found  within 
the  antrum;  but  he  believes  this  to  be  the  onlv  case  where 


140  INTERNAL  ANATOMY    OF   THE    FACE. 

three  such  teeth  have  been  reported.  In  the  lower  jaw  im- 
pacted teeth  are  Hable  to  impmge  upon  the  inferior  dental 
nerve,  thus  becoming  a  hidden  cause  of  neuralgia  in  this 
region,  which  may  have  its  symptoms  exhibited  almost  any- 
where along  the  distribution  of  the  nerves,  eventually  pro- 
ducing neuritis  that  may  pass  back  along  the  nerve  even  into 
the  brain.     (See  Figs.  ii8,  119,  120,  121.) 

Teeth  prevented  from  passing  in  their  normal  course  may, 
through  the  resorption  of  the  bone,  advance  in  almost  any 
direction  and  be  erupted  through  the  bone  even  upon  its  cer- 
vical aspect.  Impacted  or  supernumerary  teeth  may  also  pro- 
duce dental  cysts  of  various  sizes  and  forms,  some  of  which 
may  cause  the  cortical  portion  of  the  bone  to  be  pushed  out- 
ward until  large  disfiguring  tumors  are  formed.  These  have 
sometimes  been  mistaken  for  malignant  growths,  and  the  en- 
tire body  of  the  jaw  has  been  removed  on  account  of  this 
enlargement  and  the  misdiagnosis. 


MODIFICATION    OF    THE    NORMAL   SIIAPIi   OF    THE    BOXE.        I4I 


MODIFICATION  OF  THE  NORMAL  SHAPE  OF 
THE  BONE  THROUGH  ABNORMAL  FORCES. 


The  illustrations  and  descriptions  already  given  demon- 
strate that  there  are  A^ery  marked  variations  in  the  character 
of  the  bones  of  the  face,  and  of  the  sinuses  and  air  spaces  situ- 
ated in  and  between  them.  It  is  evident  that  there  must  be 
some  general  principles  underlying  these  changes. 

Causes  of  Variations  in  Shape.  At  the  beginning  of  the 
growth  of  the  embryo,  and  continuing  throughout  life,  there 
are  two  forces  constantly  acting  upon  the  body  which  may 
be  described  as  the  intrinsic  and  extrinsic;  the  former  giving 
size  and  bulk  to  the  tissues,  but  controlled  and  modified  by 
the  latter,  which,  acting  from  without,  tends  to  limit  the 
growth  and  give  form  to  the  tissues.  If  these  two  forces  be 
normal, — that  is,  properly  balanced, — in  potential  strength 
and  application  throughout  Hfe,  the  result  will  be  a  normally 
developed  organism;  but  if  these  forces  be  interfered  with  in 
any  way,  by  lack  of  nourishment  or  undue  external  pressure, 
the  individual  may  fail  to  develop  a  normal  physique. 

Deposit  of  Calcium  Salts.  If  for  some  reason  there  is  an 
insufficient  quantity  of  calcium  salts  assimilated  into  the  bony 
tissue,  the  bones  will  be  soft  and  fail  to  give  proper  shape  to 
the  body.  The  brain-case  in  such  instances  is  apt  to  enlarge 
when  the  intrinsic  growth  of  the  brain  forces  out  the  soft 
yielding  structures,  while  on  the  other  hand  an  over-amount 
of  calcium  salts  will  harden  the  bone,  and  cause  it  to  resist 
the  intrinsic  force  and  prevent  proper  development. 

In  early  life  the  undue  deposit  of  calcium  salts  will  solidify 
the  sutures  of  the  brain-case  and  prevent  the  expansion  of  the 


142 


INTERNAL    ANATOMY    OF    THE    FACE. 


brain.  Microcephalic  skulls  are  sometimes  caused  in  this  way. 
By  the  use  of  the  surgical  engine,  artificial  fissures  have  been 
made  in  the  skull,  which  allowed  the  brain-case  to  expand,  and 
thus  enabled  the  brain  itself  to  enlarge. 

The  slopes  and  forms  of  the  heads  of  the  various  races  are 
influenced  by  the  growth  of  the  brain,  and  by  artificial  means 
such  as  that  practiced  by  the  Flat-head  Indians  of  North 
America.      (See   Figs.    122   and    123.)      In   other   words,   the 

Fig.  122. 


Side  view  of  a  skull  of  Flat-head  North  American  Indian. 

brain  by  its  intrinsic  forces  acting  upon  the  bone-tissue  will 
cause  the  skull  to  expand,  according  to  the  character  of  the 
individual  race.  If  the  anterior  lobes  of  the  brain  are  of  large 
size,  the  forehead  will  be  carried  upward  and  forward;  if,  on 
the  contrary,  the  cerebellum  is  large,  the  occipital  region  will 
extend  backward,  while  the  forehead  may  be  low  and  reced- 
ing. The  two  types  are  well  illustrated  in  Fig.  124.  A  is 
taken  from  a  European  skull,  and  B  from  the  skull  of  a  Fan 


MODIFICATION    OF    THE    NORMAL    SIIAI'K    OF    THE    BONE.         I43 

Tribe  negro,  West  Africa.  Fig.  125  is  a  composite  picture 
of  these  two  skulls,  showing  their  relative  shapes.  Fig.  126 
gives  a  view  of  the  bases  of  these  two  skulls. 

Prehensile  Type  of  Dentition.  A  little  study  of  these 
specimens  brings  out  some  features  of  special  interest  to  the 
ethnologist.      In   the   savage   type  a  great   predominance   of 

Fig.  123. 


Front  view  o{  same  skull  shown  in  Fig.  122. 

development  in  the  region  of  the  cerebellum  is  found,  con- 
joined with  what  may  be  called  a  prehensile  type  of  dentition. 
This  type  was  doubtless  developed  through  continuous  use  of 
the  teeth  in  tearing  off  portions  of  the  substances  which  con- 
stitute the  food  of  the  savage  races.  The  prehensile  type 
of  dentition  is  not  found  in  the  civilized  races,  and  as  seen 
in  the  typical  skulls  the  cerebellum  is  much  less  than  in  the 
savage.  It  would  appear  reasonable  that  the  retention  of 
the  large  cerebellum — the   original  t3'pe — in  the  latter  results 


144 


INTERNAL   ANATOMY    OF    THE    FACE. 


from  the  low  standard  of  intelligence  evidenced  by  the  per- 
sistence of  the  food  habit  which  caused  the  prehensile  type  of 
dentition.  The  two  pictures  in  Fig.  1 26  show  that  the  dental  arch 
is  actually  located  further  forward  in  the  skull  of  the  savage,  A, 
than  in  that  of  civilized  man,  B.     The  anterior  portion  of  the 

Fig.  124. 


^v 


-U- 


'^  *    i    ff  "x-'Afe' 


Side  view  of  two  skulls;  A  is  of  the  Caucasian  race,  B  of  the  Fan  tribe  of  West 
Africa.  They  show  great  differences  in  conformation.  (The  Fan  tribe  skull  belongs  to 
Professor  E.  T.  Darby's  collection.) 


malar  process  of  the  maxilla  in  the  savage  is  on  a  line  with  the 
second  molar;  in  the  civilized  man  it  is  on  a  line  with  the 
second  premolar;  a  difference  equaling  the  space  of  the  first 
molar.  These  observations  are  confirmed  by  a  comparison  of 
Fig.  128,  from  the  skull  of  an  African  negro,  and  Fig.  24, 
from  the  skull  of  a  Caucasian.     It  would  seem  probable  that 


MODIFICATION    OI"    Till-:    XOKAIAL    SllAI'l':    (H"    Till':    EONE. 


145 


the  lessened  prognathism  of  the  Caucasian  race  is  one  of  the 
principal  causes  of  the  suggested  suppression  of  the  third 
molar.  An  example  of  the  occasional  rudimentary  fourth 
molar  of  the  prognathous  savage  is  seen  in  Fig.  127. 

Fig.  125. 


Composite  picture  of  the  two  skulls  shown  in  Fig.   124. 

Fig.   126. 


A  B 

Under  view  of  skulls  shown  in  Fig.   124. 


Rudimentary  or  Suppressed  Molars.  ]\Ianv  skulls  of  the 
Caucasian  races  have  only  rudimentary  third  molars;  in  some 
skulls  the  third  molar  is  entirely  lacking.  This  has  been  re- 
ceived bv  manv  writers  as  evidence  that  the  third  molar  teeth 


146  INTERNAL   ANATOMY    OF   THE    FACE. 

are  being  lost  entirely,  and  as  an  indication  that  men  will 
eventually  become  more  or  less  edentulous.  The  author  is 
of  the  opinion  that  the  teeth  of  man  are  as  good  and  fully 
formed  at  the  present  time  as  they  were  three  thousand  years 
ago;  for  if  ancient  Egyptian  skulls  are  carefully  examined, 
the  rudimentary  condition  or  complete  suppression  of  the  third 
molar  will  be  found  quite  as  frequently  as  in  skuhs  belonging 
to  relatively  the  same  class  of  people  to-day.  This  condition 
is  also  occasionally  found  in  the  North  American  Indians. 
There  is  no  difhculty  to-day  in  finding  jaws  with  thirty-two 

Fig.  127. 


X 


■4^/%. 


Side  view  of  a  prognathous  skull  of  a  negro  with  eighteen  teeth  in  the  upper  jaw. 
The  roof  of  the  mouth   is  shown   in  Fig.   128. 

perfectly  developed  teeth,  both  in  the  living  subject  and  in  the 
skuH,  with  perfect  arches,  and  occasionally  with  rudimentary 
fourth  molars,  of  which  examples  will  be  given. 

Fig.  128  shows  the  under  surface  of  the  upper  jaw  seen  in 
Fig.  127,  with  two  rudimentary  fourth  molars  in  the  line  of 
the  arch. 

Fig.  129.  The  under  surface  of  two  upper  jaws  showing  the 
occluding  surfaces  of  the  teeth,  and  their  size  relatively  to 
each  other.  B  is  about  the  normal  size,  while  A  is  very  much 
larger.  In  A  there  are  two  rudimentary  fourth  molars,  one 
in  the  line  of  the  arch  and  one  on  the  buccal  side  of  the  second 
molar. 


MODIFICATION    OF    Tril'.    NORMAL    SHAPE    OF    THE    BONE.         I47 

Fig.  128. 


The  roof  of  a  mouth  and  occluding  surface  of  eighteen  teeth,  from  same  skull  shown, 
in  Fig.   127. 

Fig.  129. 


Rudimentary 
Fourth  Molar. 


Rudimentary 
Fourth  .Molar. 


View  of  two  upper  jaws.  The  occluding  surfaces  of  the  teeth  and  roofs  of  the 
mouths,  and  the  great  difference  in  relative  size,  are  well  shown.  A  has  two  rudimentary 
fourth  molars. 


148  INTERNAL   ANATOMY    OF    THE    FACE. 

Fig.  130  is  a  view  of  the  under  surface  of  an  upper  jaw, 
showing  the  occluding  surfaces  of  the  teeth,  with  two  rudimen- 
tary fourth  molars  situated  on  the  buccal  sides  of  the  second 
molars. 

Comparison  of  flandibles  of  a  Caucasian  and  an  African 
Negro.  Fig.  131'''  affords  a  comparison  between  the  mandibles 
of  the  Caucasian  and  of  the  Fan  Tribe  negro  (West  Africa). 
They  were  photographed  upon  the  same  plate,  showing  their 

Fig.  130. 


Rudimentary 
Fourth  Molar. 


Rudimentary 
Fourth  Molar. 


View  of  the  roof  of  the  mouth  and  occluding  surfaces  of  the  teeth  from  an  ordinary- 
sized  upper  jaw,  showing  two  rudimentary  fourth  molars. 

relative  size  and  shape.  The  teeth  and  alveolar  process  in  A 
have  been  carried  much  further  forward  than  those  in  B.  In  A 
the  third  molar  is  in  advance  of  the  ramus,  while  in  B  the 
third  molar,  to  a  great  extent,  is  posterior  to  the  anterior 
margin  of  the  ramus,  the  difference  being  about  the  width  of 
a  third  molar.  Again,  in  A  the  mental  foramen  is  beneath 
the  first  molar  tooth,  while  in  B  it  is  beneath  the  interspace 
between  the  two  premolars,  again  a  difference  of  about  the 
width  of  a  molar  tooth. 

*Fig.  131  is  a  repetition  of  Fig.  2. 


MODIFICATION    OI"    TJII'.    XOKiMAF.    SIlAl'l':    Ol'    THE    UONE.  I49 

Fig.   131. 


/-\    / 


Two  mandibles,  A  from  the  Fan  tribe,  West  Africa,  B  from  a  Caucasian,  showing 
the  difference  in  the  position  of  the  teeth  in  relation  to  the  ramus,  the  mental  foramen, 
and  the  symphysis  menti. 


150  INTERNAL    ANATOMY    OF    THE    FACE. 


THE  INFLUENCE  OF  MUSCULAR  ACTION. 


After  the  birth  of  the  child,  muscular  action  and  various 
forces  have  direct  influence  over  changes  in  the  shape  of  the 
bones,  according  to  the  following  rules: 

The  normal  application  of  the  forces  affecting  developing 
bone  results  in  normal  development  of  the  form  of  the  bone. 
Their  abnormal  application  under  the  same  circumstances  re- 
sults in  the  development  of  abnormally  formed  bone.  Ab- 
normal application  of  forces  to  the  bone  in  adult  life  will  also 
change  and  modify  the  shape  and  character  of  the  bone  tissue. 
The  changes  which  may  be  caused  by  the  application  of  ab- 
normal forces  to  the  developing  individual  are  well  illustrated 
by  the  disfigurements  resulting  from  the  tight  bandages  put 
upon  the  feet  of  Chinese  girls  of  the  higher  class,  the  use  of 
corsets  to  contract  the  waists  of  the  European  women  of  the 
analogous  class,  and  the  flattening  of  the  skulls  of  certain 
Indians  of  North  America  by  binding  boards  upon  the  heads 
of  the  children.  Fig.  122  gives  a  side  view  of  one  of  these 
Indians.  Fig.  123  gives  a  front  view,  showing  that  by  the 
compression  of  the  frontal  region  downward  the  skull  has 
been  extended  laterally. 

The  modification  of  the  bones  by  abnormal  muscular  action 
is  well  illustrated  by  the  changes  found  in  persons  suffering 
from  true  or  false  ankylosis  of  the  temporo-mandibular  articu- 
lation. The  illustrations  which  follow  are  taken  from  a  pa- 
tient and  from  the  bones  of  two  skulls. 

False  Ankylosis.  Fig.  132  is  from  the  photograph  of 
a  patient  who  has  been  suffering  from  false  ankylosis. 
Judging  from  the  general  outline  of  the  face,  with  its  pro- 


THE    IXFLrKXtK    OF    MISCLLAK    ACTIOX. 


i=;i 


trnding-  lips  and  receding;-  chin,  one  might  be  inchncd  to  clas- 
sify the  individual  as  a  degenerate,  but  the  writer  believes 
that  this  picture,  and  others  to  follow,  show  that  this  is  a 


Fig.  132. 


Characteristic  appearance  in  the  region  of  the  lower  jaw  in  long-standing  ankylosis. 

Fig.  133. 


Opposite   side  of   face   of    Fig.    132,  showing   scar   caused   by  a  gunshot    wound,    the 
effects  of  which  produced  false  ankylosis. 

typical  face  belonging  to  those  who  have  or  who  have  had 

ankylosis  of  the  jaw,  either  true  or  false.     This  patient  has 

suffered  from  a  false  ankylosis  since  about  nine  years  of  age. 

Fig.    133  is  taken  from  the  right   side  of  the   same  face, 


152  INTERNAL   ANATOMY    OF    THE    FACE. 

showing  a  scar  extending  upward  and  backward  from  the 
angle  of  the  mouth  to  the  region  of  the  external  auditory 
meatus.  The  scar  was  produced  by  a  gunshot  wound.  The 
shot  in  passing  severed  the  masseter  muscle  as  well  as  a  por- 
tion of  the  buccinator.  In  the  healing  of  the  tissues  false 
bands  were  formed,  extending  from  the  lower  jaw  to  the 
malar  bone  and  the  zygomatic  arch.  The  pterygo-mandibular 
ligament  was  also  shortened,  thus  preventing  the  jaws  from 
being  opened.  The  treatment  for  the  false  ankylosis  consisted 
in  cutting  the  false  bands  and  using  the  mouth-gag  with  a 
screw  to  break  up  the  false  ligaments.  The  operator  was 
afterward  assisted  by  the  patient  in  forcing  the  jaws  asunder, 
as  shown  in  Fig.  134.  The  main  object  in  using  the  appliance 
■was  to  stretch  the  temporal  and  masseter  muscles  of  both 
sides.  In  a  few  weeks  the  patient  could  open  the  jaws  without 
the  appliance,  as  shown  in  Fig.  135.  There  was  at  this  time 
sufhcient  improvement  to  permit  of  the  mastication  of  food 
and  the  proper  care  of  the  teeth.  The  condition  has  since 
been  further  improved. 

Typical  Shaped  Ankylosed  Mandible.  In  cases  of  an- 
kylosis of  the  jaw,  especially  those  of  long  duration,  certain 
changes  in  the  form  of  the  mandible  are  noticeable,  not  only 
on  the  affected  side  when  the  ankylosis  is  unilateral,  but  also 
on  the  opposite  side.  The  character  of  these  changes  is  well 
shown  in  Figs.  136  and  137.  Fig.  136  is  a  view  of  the 
unankylosed  side  of  a  typical  case  of  true  unilateral 
ankylosed  jaw.  The  condyloid  process  is  shortened  and 
its  articulating  surface  is  changed.  Instead  of  being  rounded 
at  the  top  it  has  more  of  the  shape  of  a  Gothic  arch. 
Through  this  shortening  of  the  condyloid,  the  coronoid 
process  is  apparently  elongated.  The  angle  of  the  mandible  is 
also  elongated  so  that  it  forms  a  projecting  point,  and  the  base 
of  the  bone  under  the  mental  foramen  is  considerably 
thickened.  The  mental  process  is  much  diminished  in  size 
by  recession.  The  bone  is  all  there,  but,  by  the  operation  of 
causes  to  be  referred  to,  a  metamorphosis  has  been  induced 


Ill-:  j.\i"i.ii:xci-:  of  Mrstii.AK  action. 


153 


\vhereb}'  tlie  base  of  tlie  Ijone  has  Ijeeii  Ihickened  at  the  ex- 
pense of  the  mental  process.  Owing  to  the  same  causes,  the 
base  of  the  Ijone,  l)et\veen  the  angle  and  a  point  vertically 

Fig.  134. 


Application  of  jack-screw  for  forcing   the   mouth   open   in  false   ankylosis. 

underneath  the  canine  teeth,  is  deeply  concave  in  outline  in- 
stead of  being-  nearly  straight,  as  in  the  normal  ja^^■. 

Fig.  137  is  taken  from  the  other  side  of  the  jaw  shown 
in  Fig.  136,  showing  the  condyloid  process  completely 
changed;  it  is  broadened  out,  and  is  sharply  serrated  on  the 
articulating  surface.  The  articulating  surface  of  the  glenoid 
fossa  is  also  changed  to  correspond  to  that  of  the  condvloid, 


154 


INTERNAL   ANATOMY    OF    THE    FACE. 


with  which  it  was  interlocked.  The  angle  of  the  jaw  on  this 
side  is  much  more  changed  than  on  the  opposite  side,  causing 
a  deep  depression  in  the  region  of  the  facial  notch.  The  lower 
jaw,  under  the  mental  process,  is  fuller  and  more  roughened 

Fig.  135. 


Results  of  treatment  for  false  ankylosis. 

and  the  mental  process  more  receded  than  en  the  opposite  side. 
The  concavity  of  the  base  of  the  jaw  and  the  elongated  angle 
are  readily  seen  in  the  picture  of  the  living  subject.  (Fig.  140.) 
True  Ankylosis.  Fig.  138  is  from  a  skull  with  a  complete 
or  true  unilateral  ankylosis  of  the  jaw,  taken  from  the  unan- 
kylosed  side. 


TJll':    INl'LUKNCK    OF    MUSCULAR    ACTION. 


'DD 


Fig.  139  shows  the  ankylosecl  side.     The  lower  jaw  closely 
resembles    that    shown    in     Fig.     137,    in    the    descending 

Fig.  136. 


.'v^  ^  y 
^ 


opposite  side  of  a  typical  jaw  having  a  true  unilateral  ankylosed  temporo-mandibular 
articulation. 


Fig.  137. 


4 


The  ankylosed  side  of  Fig.    i.'^6. 

Fig.   138. 


A   skull   with   a  true  ankylosis   of  the   temporo-niandibular  articulation   on   the   oppo- 
site side. 

angle,    the   receding   chin,    etc.      In    all    cases    of    prolonged 
ankylosis  it  becomes  evident  that  there  is  cause  for  the  changes 


156  INTERNAL   ANATOMY   OF   THE    FACE. 

observed  in  the  form  of  the  bones.  The  muscles  of  mastica- 
tion,— i.e.,  those  which  elevate  the  lower  jaw, — are  inactive, 
while  those  which  assist  in  depressing  the  mandible  become 
more  and  more  active  in  their  work,  in  an  endeavor  to  over- 
come the  fixation  of  the  temporo-mandibular  articulation.  By 
their  action  the  lower  jaw,  from  the  symphysis  to  the  angle, 
becomes  modified  in  proportion  to  the  contraction  of  the  de- 
pressing muscles  of  the  jaw.  Anteriorly  there  are  the  two 
genio-hyo-glossus,  the  sterno-thyroid,  the  sterno-hyoid,  the 
digastric,   the  omo-hyoid,  and  the  platysma  myoides,  all  of 

Fig.  139. 


View  of  the  ankylosed  side  of  Fig.   138. 

which  are  abnormally  active.  Their  action,  without  the 
normal  compensating  factor  of  the  mandibular  motion,  brings 
about  in  time  the  changes  noted. 

Fig.  140  is  a  picture  of  the  patient  shown  in  Figs.  132  to 
135,  showing  an  endeavor  to  open  the  mouth  by  the  assisted- 
action  of  the  muscles.    It  illustrates  the  various  muscles  under 
spasmodic  action,  indicating  how  their  frequent  use  under 
such  conditions  may  cause  alterations  in  the  form  of  the  bone. 

Changes  in  the  Temporo=MandibuIar  Articulation  other 
than  by  Ankylosis.  Teeth  becoming  diseased  or  lost  on  one 
side  of  the  jaw  cause  changes  in  the  forms  of  the  various 
bones,  through  the  necessity  of  masticating  on  the  opposite 
side  of  the  mouth,  and  the  consecjuent  use  of  the  jaws  in  an 


THE    INFLUENCE    OF    MUSCULAR    ACTION.  1 57 

abnormal  manner.  In  this  way  great  alterations  can  be  made 
in  the  temporo-mandil)nlar  articulation,  and  in  one  or  both 
glenoid  fossae.  The  eminentia  articularis  may  be  entirely  lost 
by  resorption.  The  places  of  attachment  for  the  muscles  of 
masticatioh,  as  the  coronoid  process,  the  outer  surface  of  the 
ramus,  the  angle  of  the  jaw,  etc.,  become  roughened  and 
enlarged  on  the  side  in  use,  and  smooth  and  lessened  on  the 
unused  side.  The  spaces  where  the  muscles  have  their  origin, 
as  the  external  plate  of  the  pterygoid  process,  the  under  sur- 
face of  the  zygomatic  arch,  and  the  temporal  ridge  of  the 

Fig.  140. 


The   action   of  the   superficial   depressor  muscle   of   the   mandible   in   ankylosis. 

skull,  will  also  become  enlarged  on  one  side  and  lessened 
on  the  other. 

Many  illustrations  of  this  could  be  given,  but  one  will  be 
sufficient. 

Fig.  141  is  a  view  of  the  articulation  of  the  left  side  of  the 
skull  of  an  aged  person  who  had  lost  all  the  teeth  except  three 
in  the  upper  jaw  and  three  in  the  lower  jaw.  The}^  were  not 
opposite  to  one  another  in  normal  occlusion.  In  order  that 
the  cutting  or  grinding  surfaces  of  these  teeth  could  come 
into  occlusion,  the  left  side  of  the  jaw  had  to  be  carried  for- 
ward, bringing  the  condyloid  process  of  that  side  upon  the 
articulating   eminence,   while    the   rio-lit    side   remained   in    a 


158 


INTERNAL    ANATOMY    OF    THE    FACE. 

Fig.  141. 


Modification  of  the  left  temporo-mandibular  articulation  through  the  jaw  being  forced 
forward  in  mastication  in  order  to  bring  the  remaining  teeth  in  occlusion. 

Fig.  142. 


The  right  temporo-mandibular  articulation  from   skull  shown  in  Fig.   141,   where  the 
condyloid  orocess  has  not  been  carried  forward. 


THE    INFLUENCE   OF    MUSCULAR   ACTION.  159 

nearly  normal  position,  as  shown  in  Fig.  142.  Upon  close 
examination  of  the  condyle  of  the  left  side,  it  is  found  to  be 
flattened  out,  probably  because  of  coming  in  contact  with  the 
eminentia  articularis,  thus  moving  the  point  of  articulation 
forward,  or  jumping  the  bite.  The  eminence  is  flattened  also. 
The  forces  of  mastication  of  the  left  side  were  but  little  used, 
and  accordingly  the  places  of  origin  and  insertion  of  the  mus- 
cles of  that  side  are  much  less  marked  than  the  normal; 
while  on  the  right  side,  upon  which  alone  the  function  of  mas- 
tication was  performed,  the  muscles  were  thus  overworked, 
and  the  places  of  attachment  and  of  their  origin  and  insertion 
are  strongly  marked  in  consequence. 


l6c  INTERNAL    ANATOMY    OF    THE    FACE. 


HYPERTROPHY  OF  THE  GUMS  AND  AL= 
VEOLAR  PROCESS. 


Abnormal  growth  of  the  bone  may  produce  ahiiost  the 
same  effect,  so  far  as  appearances  go.  as  the  modification 
caused  by  abnormal  muscular  action.  In  February,  1893,  Dr. 
J.  W.  Hisey,  of  Cleveland,  brought  to  the  Hospital  of  Oral 
Surgery  a  boy  of  fifteen  years.  The  boy  was  well  developed, 
bright,  intelligent,  and  well  educated.  He  was  afBicted  with 
the  most  remarkable  case  of  hypertrophy  of  the  gums  and 
alveolar  process  that  the  writer  has  seen  recorded.  The  case 
was  operated  upon  by  the  late  Professor  Garretson  and  the 
writer,  February  17  and  March  11,  1893.'^ 

Fig.  143  is  from  a  photograph  of  the  lad  taken  before  the 
operation.  As  in  the  first  picture,  shown  in  the  ankylosis 
series,  this  boy  appears  to  have  anything  but  an  intelligent 
face.  On  February  17,  Professor  Garretson  decided  that  it 
was  best  to  open  the  upper  lip  at  the  median  line  and  carry 
the  incision  around  to  the  al^e  of  the  nose.  By  the  aid  of 
the  surgical  engine  and  other  instruments,  the  portion  shown 
in  Fig.  144  was  removed  from  the  upper  jaw.  It  was  thought 
best  not  to  remove  the  abnormal  tissue  from  the  lower  jaw 
at  this  operation,  so  it  was  delayed  until  March  11,  when  the 
mass  of  tissue  shown  in  Fig.  145  was  removed  from  the  lower 
jaw.    This  last  was  accomplished  without  cutting  the  lip. 

Fig.  146  is  from  a  photograph  taken  shortly  after  the  second 
operation,  on  April  28.     Seven  weeks  after  the  operation  the 

*A  full  description  of  the  operation  will  be  found  in  the  Dental  Cosmos, 
June,   1893. 


liVPliUTROPIlY    OF    THE    GUAIS. 


i6i 


parts  were  thoroughly  healed  and  the  general  health  of  the 
patient  was  good.     He  experienced  less  difficulty  in  articulat- 


FiG.   143. 


From  the  photograph  of  a  lad  suffering  from  hypertrophy  of  the  gums  and  alveolar 
process. 

Fig.  144. 


Tissue  removed  from  upper  jaw  of  patient  shown  in  Fig.  143. 


ing  than  previous   to   the  operation,   and   the  improvement 
in  -his    speech    and    general    appearance    was    very    marked. 


1 62 


INTERNAL    ANATOMY    OF    THE    FACE. 


Artificial  dentures  were  supplied  in  due  time.     It  was  an  in- 
teresting case,  and  the  writer  has  kept  in  casual  communi- 

FiG.  145. 


Tissue  removed  from  lower  jaw  of  patient  sliown  in  Fig.   143. 


Fig.  146. 


From  a  photograph  taken  three  weeks  after  the  removal  of  tissue  as  shown  in  Figs. 
144  and  145. 


iniMCR  TKoi'in-  oi-   Till-:  (;ims.  163 

cation  witli  the  patient.  In  one  of  liis  letters,  aljout  six  years 
after  tlie  operation,  he  forwarded  his  latest  ])hotograph,  to 
afford  an  idea  of  his  g-eneral  a])pearance.  Fig.  147  is  made 
from  this  photograph.     To  jndge  from  this,  the  young  man 

Fig.  147. 


From   a  photograph   six   years   after  the   operation  upon   the  person  represented   in 
Fig.    143- 

certainly  does  not  look  like  a  degenerate.  The  operation  has 
evidently  made  a  tremendous  improvement  in  his  appearance, 
and  it  seems  to  be  conclusively  demonstrated  that  Professor 
Garretson  was  right  in  his  judgment  as  to  the  operation. 


164  INTERNAL   ANATOMY    OF   THE    FACE. 


THE  RELATION  OF  THE  TWO  JAWS. 


The  Relation  of  the  Upper  and  Lower  Jaws  Varies  Through- 
out Life.  There  is  also  a  difference  in  their  relative  time  of  de- 
velopment. The  lower  jaw  is  developed  slightly  in  advance  of 
the  upper  one  and  is  formed  from  two  processes  or  buds,  the 
upper  jaw  being  formed  from  four  processes  or  buds, — two 
from  the  sides  and  two  from  above.  Occasionally  these  four 
processes  fail  to  complete!}^  unite.  This  lack  of  union  varies 
from  a  slight  cleft  palate  or  hare-lip  to  a  double  cleft  palate 
and  double  hare-lip.  In  a  few  very  exceptional  cases  there 
has  been  an  entire  lack  of  union  of  these  parts,  leaving  the 
mouth,  nasal  chamber,  and  orbits  as  one  common  cavity. 
Various  theories  have  been  advanced  for  this  lack  of  union, 
the  most  prominent,  perhaps,  being  that  of  malnutrition  of 
the  parts  during  the  time  when  the  union  should  take  place. 
While  agreeing  that  malnutrition  is  probably  largely  responsi- 
ble, the  writer  offers  as  a  plausible  explanation  of  the  manner 
of  its  operation  the  idea  that  as  the  lower  jaw  is  formed  in  ad- 
vance of  the  upper  one,  when  undue  pressure  is  exerted  upon 
it,  it  is  forced  in  between  the  four  processes  forming  the 
upper  jaw,  thus  mechanically  preventing  them  from  coming 
together. 

The  normal  position  of  the  fetus  in  utero  is  such  that  the 
weight  of  the  entire  fetal  body  may  be  readily  thrown  upon 
the  vertex,  and  the  pressure  thus  exerted  would  tend  to  force 
the  mandible  into  contact  with  the  sternal  region  and  com- 
press the  forming  jaws  together.  The  relatively  advanced 
development  of  the  mandible,  as  compared  with  that  of  the 


Tiiic  ki:lation  of  thi-:  rwu  jaws.  165 

forming  maxilla,  would  under  the  circumstances  referred  to, 
and  especially  in  cases  of  low  nutritional  standard,  interfere 
with  the  normal  closure  of  the  brachial  arches  and  tend  to 
produce  a  permanent  coloboma. 

If  an  examination  be  made  of  a  young  child  with  a  complete 
cleft,  it  will  be  noticed  that  the  upper  alveolar  ridge  is 
immediately  over  the  alveolar  ridge  of  the  lower  jaw,  or  it 
may  be  external  to  it;  in  the  normal  child  or  in  the  person 
of  advanced  age  the  upper  alveolar  ridge  is  in  vertical  line 
within  that  of  the  lower  jaw,  as  is  well  illustrated  in  Figs. 
25  and  149  and  in  B,  Figs.  150  and  151. 

Manner  of  Drinking.  Individuals  having  cleft  palate,  es- 
pecially those  with  double  cleft,  have  not  the  power  to  drink 
when  the  anterior  portion  of  the  mouth  is  on  a  lower  level 
than  the  posterior  portion.  They  are  compelled  to  raise  the 
head,  thus  throwing  the  fluid  back  into  the  pharynx,  similar 
to  the  manner  in  which  a  chicken  drinks.  This  mode  of 
drinking  is  normal  with  the  chicken,  as  it  has  naturally  a  cleft 
palate,  and  has  not  the  power  of  suction  as  performed  in  man 
by  his  palato-glossus  muscles.  A  child  with  a  complete  cleft 
has  no  power  of  suction  with  the  lips.  If  the  artificial  nipple 
be  long  and  large,  in  order  that  the  child  may  seize  it  with 
the  palatal  muscles,  it  will  have  the  power  of  sucking  or  of 
drawing  the  fluid  through  the  nipple. 

Mold  upon  which  the  Maxilla  is  Formed.  It  is  generally 
accepted  that  the  lower  jaw  acts  as  a  matrix  or  mold  upon 
which  the  uJDper  jaw  is  formed.  It  certainly  to  an  extent 
becomes  the  mold  upon  which  the  inferior  border  of  the  upper 
jaw  is  formed,  as  the  latter  comes  in  contact  with  its  inner 
edges.  This  action  also  influences  the  general  contour  and 
shape  of  the  superior  alveolar  ridge  and  roof  of  the  mouth. 

Fig.  148  is  a  picture  taken  from  the  skull  of  a  fully  devel- 
oped fetus.  The  skull  has  been  cut  vertically  and  transversely 
in  the  region  of  the  developing  deciduous  teeth  of  both  jaws, 
showing  the  jaws  in  transverse  section.  The  skull  is  quite 
symmetrical.     It  is  plainly  to  be  seen  that  the  width  of  the 


1 66 


INTERNAL   ANATOMY    OF    THE    FACE. 


Upper  jaw  is  much  less  than  that  of  the  lower. "^  As  a  further 
evidence  of  this  fact,  if  vertical  lines  are  drawn  through  the 
centers  of  the  tooth-germs  and  the  alveolar  process  of  each 
jaw,  it  will  be  found  that  the  lines  of  the  upper  jaw  are  on  the 
inner  side  of  those  of  the  lower  jaw,  the  extent  of  the  differ- 
ence being  about  one-half  of  the  thickness  of  the  lower  jaw. 

Fig.  148. 


Anterior  Fossa 
'/M^J-    0/  .Brain-Case. 
./!P-j»'     sf/"™    Crista  Gain. 

—    Orbit. 

Nasal  Septum. 


Ostium  Maxillare. 
Maxillary  Sinus. 
Malar  Bone. 
Maxilla. 

Dental   Germs. 


Mandible. 


Hard  Palate. 


Vertical  transverse  section  through  the  orbits,  the  nasal  chamber,  and  the  pre- 
molar teeth. 

Fig.  149  is  taken  from  an  adult  jaw.  If  the  lines  be  drawn 
through  the  axes  of  the  upper  and  the  lower  teeth,  it  will  be 
found  that  those  through  the  upper  teeth,  as  they  extend  to- 
ward the  coronal  surfaces,  pass  a  little  outward,  while  those 
passing  up  through  the  lower  teeth  incline  inward.     This  is 


*For  description  of  other  features  shown  in  this  illustration,  see  Fig.  40. 


Till':  Ki-:LArioN  of  riiK  two  taws. 


167 


evidence  that  the  relation  found  in  the  fetus  has  been  con- 
tinued, and  that  all  through  the  period  of  growth  of  the 
lower  jaw  and  development  of  its  alveolar  process,  the  latter 
has  been  directed  inward,  while  the  upper  alveolar  process  has 
extended  outwardly,  so  that  the  cusps  of  the  upper  permanent 
teeth,  when  fully  developed  normally,  bite  over  the  outer  cusps 
of  the  lower  teeth  occluding  with  them.  If  the  teeth  and 
alveolar  process  be  excluded,  it  will  be  observed,  as  in  the  fetal 
skull,  that  the  upper  jaw  is  much  smaller  than  the  lower.  The 
same  characteristics  will  be  found  more  markedly  shown  in 
Fig.  25. 

Fig.  149. 


Anterior  view  of  a  vertical   transverse   section  through  the  lower  jaw   and  the  lower 
portion  of  the  upper  jaw. 


The  Resorption  of  the  Alveolar  Processes.  As  the  alveolar 
process  belongs  to  the  teeth  and  is  developed  with  them, 
and  its  function  is  that  of  holding  them  in  position,  it  disap- 
pears to  a  greater  or  less  extent  after  the  teeth  are  lost.  The 
manner  of  its  resorption  differs  in  the  two  jaws.  In  the  upper 
the  external  plate  disappears  more  rapidly  than  the  internal, 
which  persists  for  a  considerably  longer  period,  though  in  ex- 
treme old  age  the  entire  process  is  lost,  leaving  a  very  narrow 
jaw  and  a  small  roof  to  the  mouth.     (See  B,  Figs.  150  and 

151.) 


l68  INTERNAL    ANATOMY    OF    THE    FACE. 

In  the  lower  jaw  the  resorption  of  the  two  plates  takes 
place  more  evenly.  Usually  they  are  resorbed  in  such  a  man- 
ner that  a  slight  ridge  is  left  between  the  places  which  they 
formerly  occupied. 

The  Relations  in  Extreme  Old  Age.  As  a  result,  we  find 
a  twofold  effect  upon  the  relation  of  the  jaws.  As  the  resorp- 
tion of  the  alveolar  process  goes  on,  the  vertical  distance 
JDetween  the  body  of  the  lower  jaw  and  that  of  the  upper  is 
lessened,  while  the  natural  difference  in  their  width  is 
increased.  The  area  of  the  upper  jaw  becomes  smaller  in 
proportion  to  that  of  the  lower,  the  axes  of  the  mandible  ex- 
tending further  outward.  In  the  endeavor  to  close  the  jaws 
under  these  circumstances,  the  lower  is  projected  further  for- 
ward as  it  rises  to  meet  the  upper,  until,  in  extreme  cases,  it 
may  pass  absolutely  outside  of  the  upper.  This  is  a  frequent 
characteristic  of  the  edentulous  jaw  in  old  age. 

If  properly  fitting  artificial  dentures  are  placed  in  the  mouth 
promptly  after  the  loss  of  the  natural  teeth,  the  resorption 
of  the  alveolar  process,  and  particularly  the  change  in  the 
angle  of  the  jaw,  will  be  retarded.  Thus,  if  these  teeth  are 
replaced  from  time  to  time  by  dentures  adjusted  to  the  condi- 
tions as  the  processes  recede,  this  characteristic  change  of 
old  age  will  be  overcome  to  a  very  considerable  extent. 

Fig.  150  is  taken  from  two  skulls  of  about  the  same  shape 
and  size.  A  is  from  an  adult  of  about  twenty-five  years,  hav- 
ing a  full  set  of  normally  occluded  teeth.  The  direction  of  the 
upper  and  lower  teeth  can  be  observed  as  described.  B  is 
from  a  person  of  seventy-five  years  or  more,  where  all  the  teeth 
were  lost  and  the  alveolar  process  resorbed  long  before  death, 
showing  the  upper  and  lower  jaws  in  their  normal  shape  and 
relations. 

Fig.  151  is  a  side  view  of  the  same  skulls  shown  in  Fig.  150. 
It  seems  evident  from  these  skulls,  which  are  typical  and  not 
exceptional,  that  if  the  teeth  be  lost  and  the  alveolar  process 
resorbed  after  middle  life,  the  upper  and  lower  jaws  cannot 
be  again  brought  into  occlusion  through  their  alveolar 
borders. 


THE    RFJ^ATION    OF    TIIF.    TWO    JAWS. 


169 


Causes  of  Malformation  of  the  Jaws.       Ilic  normal   action 
and  reaction  between  the  two  jaws  has  been  spoken  of  as  pro- 

FiG.  150. 


Under  view  of  two  adult   skulls.     A  from  a   subject  about  twenty  years  old,   B  from 
one  well  advanced  in  years. 


Fig.  151. 


A  B 

Side  view  of  the  two  skulls  shown  in  Fig.  150. 


I70  INTERNAL   ANATOMY    OF   THE    FACE. 

ducing  irregularities  in  the  shape  of  the  arches,  of  the  roof  of 
the  mouth,  and  in  the  position  of  the  teeth.  In  general,  it 
may  be  said  that  any  cause  which  prevents  the  normal  occlu- 
sion of  the  jaws,  during  either  rest,  speech,  or  mastication, 
will  bring  about  malformation  of  these  parts.  Among  the 
causes  which  prevent  the  normal  bringing  together  of  the 
jaws  may  be  mentioned  mouth-breathing,  inflammation  of  the 
bone,  of  its  periosteum  or  of  the  pericementum,  or  conditions 
causing  pain  when  the  teeth  come  in  contact.  Mouth-breath- 
ing should  be  corrected,  whether  it  is  caused  by  bony  obstruc- 
tion, hypertrophy  of  the  mucous  membrane,  or  adenoid 
growths;  in  or  about  the  naso-pharyngeal  space.  While  the 
jaws  are  kept  asunder  the  muscles  in  connection  with  the 
orbicularis  oris  are  somewhat  tightened,  and  a  pressure  which 
has  a  tendency  to  force  the  teeth  inward  is  brought  to  bear 
upon  the  non-occluding  teeth,  causing  malocclusion. 

While  this  feature  of  the  lateral  pressure  of  the  muscles  of 
expression  as  a  cause  of  irregularity  in  the  upper  dentures  of 
mouth-breathers  has  received  very  general  acceptance,  it 
is,  in  the  opinion  of  the  writer,  merely  an  incidental  factor, 
and  of  far  less  etiological  importance  than  the  loss  of  the 
developing  and  molding  influence  which  directly  results  from 
the  percussive  force  of  occlusion  exerted  by  the  mandible 
upon  the  maxillary  arch.  The  presence  of  adenoid  growths 
in  the  naso-pharynx,  or  in  fact  any  cause  which  interferes 
with  the  normal  closing  of  the  mouth,  at  once  interferes 
with  occlusion,  which,  in  view  of  more  recent  studies,  the 
writer  regards  as  the  most  potent  factor  in  the  normal 
development  of  the  relation  of  the  upper  to  the  lower  den- 
tures. 

It  is,  of  cotirse,  to  be  understood  that  the  factor  behind 
these  anatomical  variations,  leading  to  asymmetrical  develop- 
ment, is  necessarily  nutritional.  Some  interference  with  local 
nutrition  has  brought  about  functional  disturbance  of  a  part, 
and  this,  in  turn,  a  corresponding  modification  of  anatomical 
form. 


THE    RELATION    t)F    THE   TWO    JAWS.  I7I 

The  writer  trusts  that  the  data  which  are  embodied  in  this 
work  will  not  be  regarded  as  exhaustive  of  the  subject,  but 
rather  as  an  indication  of  the  magnitude  of  the  field  to  be 
studied,  and  more  particularly  as  suggestive  of  the  rational 
method  by  which  the  subject  should  be  studied, — viz.,  by 
actual  dissection  of  anatomical  specimens. 


INDEX. 


Abnormal  growths  in  bones  of  head, 

neuralgia  from,  5. 
Age,  change  of  shape  of  sknll  in,  2, 

168. 
Air  cells  with  outlet  into  nasal  fossae, 

86,  87. 
Alveolar  process,   description   of,   32, 

34- 
disappearance  of.  33. 
hypertrophy  of.  160. 
internal  plate  to  be  preserved,  34. 
resorption  of,  167. 
Anatomical  structures,  4. 
Anatomical  variations,  i,  89. 

surgical  mishaps  through,  3. 
Anatomy,  typical,  of  bony  structures 

of  face,  35. 
Angle  of  mandible,  changes  in,  6,  152. 
Ankylosis,  effect  of  on  mandible,  152. 
false,  150. 
true,  154. 
Anterior  ethmoidal  cells,  87,  107. 

wall  of  maxillary  sinus,  61. 
Antral  variations,  67,  70,  89,  94,   100, 

102,  III. 
Antrum  of  Highmore,  59. 
infection  of,  73. 

walls  of,   thicker  in  negro   than  in 
white  races,  39,  104. 
Architectural  features  of  maxillfe,  31. 
Articulation,  changes  in  from  abnor- 
mal muscular  action,  156. 
ideal,  41. 
Asymmetry,  3,  89. 

Atrophy    of    nerves    from    abnormal 
growths  in  bones  of  head,  5. 

Bilateral  symmetry,  35,  47,  93. 
Body  of  mandible,  description  of.  8. 
Bone,   causes  of  variations  in   shapes 
of.  141. 
decalcification  of.  60. 
deficiency  of  calcium  salts  in,  141. 
modifications   in   shapes   of,    i,    141, 
150. 


Bones,  bilateral,  3. 

homonymous,  3. 

mucous    and    non-mucous    surfaces 
of,  4. 
Bulla  ethmoidalis,  87. 

pathological  conditions  of,  113. 

Calcium  salts,  deposit  of,  141. 

Canals  in  bones  of  head,  5. 

Cancellated  bone,  function  of,  5.  43. 
resorption  of.  60. 

Cancellated  structure  of  mandible, 
cast  of,  19. 

Cell  of  the  crista  galli,  88.  96,  100,  107, 
119. 

Cells,  ethmoidal,  87. 
of  orbital  process.  87. 

Changes  in  the  temporo-mandibular 
articulation  other  than  by  ankylo- 
sis, 156. 

Cleft  palate,   effect  of  on   manner  of 
drinking,  165. 
probable  cause  of,  164. 

Climate  modifying  shape  of  skull.  2. 

Comparison  of  mandibles  of  a  Cau- 
casian and  a  South  African  ne- 
gro, 148. 

Cortical  bone.  4.  8. 

Cribriform  bone.  9. 

Cribriform  tube  of  mandible,  11. 
branches  of,  12,  15. 

Dental  relations  of  maxillary  sinus. 

Dentition,  civilized  and  savage  types 
of,  143. 

Development    affected    by    forces    of 
growth,    150. 
of  maxillary  sinus,  59. 

Diagnosis  of  impacted  teeth,  136. 

Diagnostic  importance  of  variations.  3. 

Diet,  influence  of  on  the  bony  struc- 
tures. 2. 

Disease,  influence  of  in  changing  the 
bony  structures,  2. 

173 


174 


INDEX. 


Effects  of  pathological  conditions  in 
the  hiatus  semilunaris,   113. 

Egyptian  skulls,  rudimentary  or  sup- 
pressed molar  teeth  of,  146. 

Empyema  of  antrum  from  drill  pass- 
ing through  wall  of  root,  39. 

Engine,  surgical,  advantages  of,  31. 

Equilateral  triangle,  29. 

Ethmoidal  cells,  86,  87. 

Eustachian  tubes,  fluids  from,  46. 

Extraction  of  impacted  teeth,  136. 
of  teeth,  causes  for  accidents  in,  18, 
23,  25,  38. 

Failure  of  surgical  operations  due  to 

variations,  i. 
False  ankylosis,  treatment  of,  150. 
Fifth  meatus.  58. 
Floor  of  maxillary  sinus,  61. 
Fractures   of   the  floor   of   maxillary 

sinus,  78. 
Frontal  sinus,  55,  82,  102. 

development  of.  82. 

occlusion  of  outlet  of,  117. 

General  considerations,  4. 
Gonion  of  lower  jaw,  6. 

Hiatus  semilunaris.  55,  98,  104,  113. 
pathological  conditions  of,  80,   113. 
Hypertrophy    of   gums    and    alveolar 
process,  160. 

Impacted  teeth,  canine,  126,  127,  129. 
causing   resorption   of  other  teeth, 

134- 

central  incisor,   125,   126,   130. 

diagnosis  of.   136. 

extraction  of,  136. 

from   interference   in    development, 
122. 

lateral  incisor,  126. 

lesions  from,  139. 

loss  of  teeth  due  to.  127. 

lower  third  molar,  132,  133,  136. 

neuralgia  from,  139. 

nutritional    changes    as    cause    for, 
123. 

supernumerary  teeth  caused  by,  123. 

supernumerary  lateral,  130. 

upper  third  molar,  129,  130,  132,  133, 
136. 
Impaction  of  teeth  due  to  inflamma- 
tory processes,  25. 
Infection,  extension  of  from  roots  of 
teeth,  18,  'JT,. 

of  antrum  through  careless  operat- 
ing, 24,  78. 


Inferior  dental  canal,  11. 
dental     nerve,     resection    of,     how 

complicated,  14. 
maxillary  bone,  6. 
meatus,  49. 
Inflammatory  changes  from  diseased 
teeth,  24. 
conditions  from  impacted  teeth,  133. 
Influence  of  age,  climate,  diet,  etc.,  2. 
of  hydrogen  dioxid  upon  the  can- 
cellated tissue  of  the  bone,  19. 
of  muscular  action,    150. 
Infraorbital  canal,  position  of,  42,  63. 
Infundibulum,  55. 
Interference  in  development  cause  of 

impacted  teeth,  122. 
Introductory,  i. 

Jaws,  malformation  of,  169. 

properly    fitting    artificial    dentures 

of,_  168. 
relation  of,  in  old  age,  168. 
relations  of,  164. 

Lachrymal  duct,  46.  49,  52. 

Loss  of  teeth  due  to  impaction,  127. 

Malnutrition  as  cause  for  cleft  pal- 
ate, 164. 
Mandible,  angle  of.  6. 

comparative  thickness  of,  4. 

development    of,     permanently    re- 
corded, 15. 

effect  of  ankylosis  on,  152. 

inflamed  condition  of,  25. 

inflammatory  changes,  24. 

methods  of  growth.  13. 

necrosis  and  regeneration  of.  2(i. 

passage  of  nerves  in  cribriform  tube 
of.  I5-. 

pathological  significance  in  anatomi- 
cal arrangements  of,  15,  17. 

secondary  deposits  in  structure  of, 
26. 

shape  of,  changed  by  muscular  ac- 
tion, 156. 

surgical   significance  of  anatomical 
arrangement  of,  14. 

the   mold  on   which   the   maxilla   is 
formed.  165. 

typical  shaped  ankylosed.   152. 
Mandibles.  Caucasian  and  African  ne- 
gro, 148. 
Mandibular   triangle   not    equilateral, 

28. 
Maxilla,  alveolar  process  of,  32. 

architectural  features  of,  31. 

description  of,  31. 


INDEX. 


/D 


Alaxilla,     mold     upon     which     it     is 
formed,  165. 

pathological  relations  of,  32. 

removal  of,  31. 
Maxillary  sinus,  anterior  wall  of,  f)\. 

dental  relations  of,  72. 

description  of,  59. 

development  of,  59. 

floor  of,  61. 

ostium  maxillare,  63. 

outer  wall  of,  62. 

posterior  or  zygomatic  wall  of,  62. 

proximal  or  nasal  wall  of,  63. 

septa  of,  38,  62,  64. 

superior  wall  or  roof  of,  62. 

surgical  relations  of,  78. 
Meati,  number  of,  49. 
Meatus,  first  or  inferior,  49. 

second  or  middle,  54. 

third  or  superior,  58. 

fourth  or  supreine,  58. 

fifth,  58. 
Mental  foramen,  recurrent  tube  to,  12. 
Metal  casts  of  internal   structures  of 

the  mandible,  19. 
Middle  ethmoidal  cells,  87. 

meatus,  54. 
Modifications  of  normal  shape  of  bone 

through  abnormal  forces,  141. 
Mucoid  surfaces,  4. 
Muscular  action,  influence  of,  150. 

Nasal  canals,  49. 

Nasal  fossae,  description  of,  46. 

floor  of,  47. 

meati  of,  49. 

roof  of,  47. 

septal  spurs  of,  48. 

septum  of,  48. 

variations  of,  102. 
Nasal  meati,  49. 

septum,  48. 
Neuralgia  due  to  impaction  of  teeth, 

139- 
from  secondary  bone  deposit,  26. 
Neuralgic  affections  from  growths  in 
foramina  and  canals  of  bones  of 
head,  5. 
Neuromata  of  inferior  dental  nerve,  15. 
Non-mucous  surfaces,  4. 
Normality,    necessity    of    recognizmg 

departures  from  recognized,  30. 
Nutritional     changes,     impaction     of 
teeth  due  to,  123. 
supply  of  the  teeth,  12,  43. 
of  pericementum,  16. 

Obstruction  of  fluids,  119. 


Occlusion,  ideal,  of  teeth,  35. 
of  the  outlets  of  the  frontal  sinus. 

Occupation,     inllucnce     of    on     l)ony 

structure,  2. 
Old  age,  relation  of  jaws  in,  168. 
Olfactory  organs,  47,  49. 
Osteoblasts,  action  of,  24. 
Osteophytes,  53,  67. 
Ostium  maxillare,  description  of,  6^. 
Outer  wall  of  maxillary   sinus,  62. 

Pathological  condition  of  bulla  eth- 

moidalis,  80,  113. 
significance    of    recurrent     inferior 

dental  nerve,  15. 
Pericementum,   nutritional   supply  of, 

16. 
Posterior  ethmoidal  cells,  87,  98. 

wall  of  maxillary  sinus,  62. 
Prehensile  type  of  dentition.  143. 
Prognathism,    lessened,    as   cause   for 

suppression  of  third  molar,  144. 
Proximal  or  nasal  wall  of  maxillary 

sinus,  6s. 
Pulp   hypertrophy  and   congestion   of 

peridental  membrane,  17. 

Recurrent  branches  of  the  cribriform 

tube,   14. 
Regeneration  of  bone,  26. 
Relations  of  roots  of  teeth  and  walls 
of  antrum  different  in  white  and 
negro  races,  38,  39. 
of  the  jaws,  164. 
Relative  depth   of  insertion  of  teeth 

roots  in  jaws,  9,  10,  22,  23. 
Resection    of    inferior    dental    nerve, 

how  complicated,  14,  27. 
Resorption  of  alveolar  process,  167. 
Roots  of  teeth,   depth   of  in   alveolar 
process,  9,  10,  23. 
impinging  on  inferior  dental  canal, 

27. 
in  floor  of  maxillary  sinus,  38,  64. 
passing  through  walls  of  jaw,  27. 
position   of   in   alveolar   process,   9, 
10,  22,  23. 
Rudiinentary     or     suppressed     molar 
teeth,  145. 

Secondary  bone  deposits,  26. 
Septa  of  maxillary  sinus,  64. 
Septal  spurs,  48,  100,  106. 
Skull,  ideal,  35. 

typical,  35. 
Sockets  of  the  teeth,  9,  33. 


176 


JNDEX, 


Sphenoidal  sinus,  87. 

fluids  from,  58. 

large,  70,  71. 
Submaxillary  triangle,  28. 
Superior  meatus,  58. 

wall  or  roof  of  maxillary  sinus,  62. 
Supernumerary  teeth  causing  impac- 
tion, 123. 
Suppressed  rudimentary  molar  teeth, 

145- 
Supreme  meatus,  58. 
Surgical  pathology  in  relation  to  roots 
in  mandible,  18,  25. 
relations  of  maxillary  sinus,  78. 
significance  of  recurrent  branches  of 
cribriform  tube,  14. 

Teeth,  diseased,  24,  T},. 

permanent  and  deciduous,  relations 

of,  at  six  years.  40. 
relation  of,  to  alveolar  process,  9, 

10.  22,  23. 
rudimentary    or    suppressed   molar, 

145- 
sockets  of,  9,  33. 


Temporo-mandibular  articulation, 

change  in  shape  of,  153,  156. 

Trabeculse  in  the  jaws,  5. 

Typical  shaped  ankylosed  mandible, 
152. 

Upper  jaw,  31. 

alveolar  process  of,  32. 
alveoli  of,  ZZ- 

architectural  features  of,  31. 
inner  plate  of,  33. 
pathological  relations  of,  32. 
resorption    of    alveolar    process    of, 

outer  plate  of,  2>2>- 
U-shaped  portion  of  mandible,  8. 

Variations,  anatomical,  i. 
causes  of,  141. 

of  the  anatomical  structures  of  the 
face.  89. 

Zygomatic  wall  of  the  maxillary 
sinus,  62. 


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